System.Data.SQLite

      </table>
    </div>
    <div id="mainSection">
    <div id="mainBody">
    <h1 class="heading">Version History</h1>
    <p><b>1.0.89.0 - September XX, 2013 <font color="red">(release scheduled)</font></b></p>
    <ul>
      <li>Updated to <a href="http://www.sqlite.org/src/info/trunk">SQLite 3.8.1</a>.</li>
    </ul>
    <p><b>1.0.88.0 - August 7, 2013</b></p>
    <ul>
      <li>Various fixes to managed virtual table integration infrastructure.</li>
      <li>Implement workaround for an incorrect PROCESSOR_ARCHITECTURE being reported. Fix for <a href="http://system.data.sqlite.org/index.html/info/9ac9862611">[9ac9862611]</a>.</li>
      <li>Modify classes that implement the IDisposable pattern to set the disposed flag after their base classes have been disposed.</li>
      <li>When automatically registering custom functions, use the executing assembly (i.e. System.Data.SQLite) for reference detection. Fix for <a href="http://system.data.sqlite.org/index.html/info/4e49a58c4c">[4e49a58c4c]</a>.</li>

<?xml version="1.0" encoding="utf-8"?>
<!--
 *
 * sqlite3.props -
 *
 * Written by Joe Mistachkin.
 * Released to the public domain, use at your own risk!
 *
-->
<Project DefaultTargets="Build" xmlns="http://schemas.microsoft.com/developer/msbuild/2003" ToolsVersion="4.0">
  <PropertyGroup Label="UserMacros">
    <SQLITE_MANIFEST_VERSION>3.8.1</SQLITE_MANIFEST_VERSION>
    <SQLITE_RC_VERSION>3,8,1</SQLITE_RC_VERSION>
    <SQLITE_COMMON_DEFINES>_CRT_SECURE_NO_DEPRECATE;_CRT_SECURE_NO_WARNINGS;_CRT_NONSTDC_NO_DEPRECATE;_CRT_NONSTDC_NO_WARNINGS;SQLITE_THREADSAFE=1;SQLITE_USE_URI=1;SQLITE_ENABLE_COLUMN_METADATA=1;SQLITE_ENABLE_STAT3=1;SQLITE_ENABLE_FTS3=1;SQLITE_ENABLE_LOAD_EXTENSION=1;SQLITE_ENABLE_RTREE=1;SQLITE_SOUNDEX=1</SQLITE_COMMON_DEFINES>
    <SQLITE_EXTRA_DEFINES>SQLITE_HAS_CODEC=1</SQLITE_EXTRA_DEFINES>
    <SQLITE_WINCE_DEFINES>SQLITE_OMIT_WAL=1</SQLITE_WINCE_DEFINES>
    <SQLITE_DEBUG_DEFINES>SQLITE_DEBUG=1;SQLITE_MEMDEBUG=1;SQLITE_ENABLE_EXPENSIVE_ASSERT=1</SQLITE_DEBUG_DEFINES>
    <SQLITE_RELEASE_DEFINES>SQLITE_WIN32_MALLOC=1</SQLITE_RELEASE_DEFINES>
    <SQLITE_DISABLE_WARNINGS>4055;4100;4127;4146;4210;4232;4244;4245;4267;4306;4389;4701;4703;4706</SQLITE_DISABLE_WARNINGS>
    <SQLITE_DISABLE_X64_WARNINGS></SQLITE_DISABLE_X64_WARNINGS>

<VisualStudioPropertySheet
	ProjectType="Visual C++"
	Version="8.00"
	Name="sqlite3"
	>
	<UserMacro
		Name="SQLITE_MANIFEST_VERSION"
		Value="3.8.1"
		PerformEnvironmentSet="true"
	/>
	<UserMacro
		Name="SQLITE_RC_VERSION"
		Value="3,8,1"
		PerformEnvironmentSet="true"
	/>
	<UserMacro
		Name="SQLITE_COMMON_DEFINES"
		Value="_CRT_SECURE_NO_DEPRECATE;_CRT_SECURE_NO_WARNINGS;_CRT_NONSTDC_NO_DEPRECATE;_CRT_NONSTDC_NO_WARNINGS;SQLITE_THREADSAFE=1;SQLITE_USE_URI=1;SQLITE_ENABLE_COLUMN_METADATA=1;SQLITE_ENABLE_STAT3=1;SQLITE_ENABLE_FTS3=1;SQLITE_ENABLE_LOAD_EXTENSION=1;SQLITE_ENABLE_RTREE=1;SQLITE_SOUNDEX=1"
		PerformEnvironmentSet="true"
	/>

/******************************************************************************
** This file is an amalgamation of many separate C source files from SQLite
** version 3.8.1.  By combining all the individual C code files into this 
** single large file, the entire code can be compiled as a single translation
** unit.  This allows many compilers to do optimizations that would not be
** possible if the files were compiled separately.  Performance improvements
** of 5% or more are commonly seen when SQLite is compiled as a single
** translation unit.
**
** This file is all you need to compile SQLite.  To use SQLite in other

** string contains the date and time of the check-in (UTC) and an SHA1
** hash of the entire source tree.
**
** See also: [sqlite3_libversion()],
** [sqlite3_libversion_number()], [sqlite3_sourceid()],
** [sqlite_version()] and [sqlite_source_id()].
*/
#define SQLITE_VERSION        "3.8.1"
#define SQLITE_VERSION_NUMBER 3008001
#define SQLITE_SOURCE_ID      "2013-08-29 01:09:14 9229aeb361f9805894321327d05aba855b8799f3"

/*
** CAPI3REF: Run-Time Library Version Numbers
** KEYWORDS: sqlite3_version, sqlite3_sourceid
**
** These interfaces provide the same information as the [SQLITE_VERSION],
** [SQLITE_VERSION_NUMBER], and [SQLITE_SOURCE_ID] C preprocessor macros

# define SQLITE_DEFAULT_MMAP_SIZE_xc 1  /* Exclude from ctime.c */
#endif
#if SQLITE_DEFAULT_MMAP_SIZE>SQLITE_MAX_MMAP_SIZE
# undef SQLITE_DEFAULT_MMAP_SIZE
# define SQLITE_DEFAULT_MMAP_SIZE SQLITE_MAX_MMAP_SIZE
#endif

/*
** Only one of SQLITE_ENABLE_STAT3 or SQLITE_ENABLE_STAT4 can be defined.
** Priority is given to SQLITE_ENABLE_STAT4.  If either are defined, also
** define SQLITE_ENABLE_STAT3_OR_STAT4
*/
#ifdef SQLITE_ENABLE_STAT4
# undef SQLITE_ENABLE_STAT3
# define SQLITE_ENABLE_STAT3_OR_STAT4 1
#elif SQLITE_ENABLE_STAT3
# define SQLITE_ENABLE_STAT3_OR_STAT4 1
#elif SQLITE_ENABLE_STAT3_OR_STAT4
# undef SQLITE_ENABLE_STAT3_OR_STAT4
#endif

/*
** An instance of the following structure is used to store the busy-handler
** callback for a given sqlite handle. 
**
** The sqlite.busyHandler member of the sqlite struct contains the busy
** callback for the database handle. Each pager opened via the sqlite
** handle is passed a pointer to sqlite.busyHandler. The busy-handler

  Expr *pPartIdxWhere;     /* WHERE clause for partial indices */
  int tnum;                /* DB Page containing root of this index */
  u16 nColumn;             /* Number of columns in table used by this index */
  u8 onError;              /* OE_Abort, OE_Ignore, OE_Replace, or OE_None */
  unsigned autoIndex:2;    /* 1==UNIQUE, 2==PRIMARY KEY, 0==CREATE INDEX */
  unsigned bUnordered:1;   /* Use this index for == or IN queries only */
  unsigned uniqNotNull:1;  /* True if UNIQUE and NOT NULL for all columns */
#ifdef SQLITE_ENABLE_STAT3_OR_STAT4
  int nSample;             /* Number of elements in aSample[] */
  int nSampleCol;          /* Size of IndexSample.anEq[] and so on */
  tRowcnt *aAvgEq;         /* Average nEq values for keys not in aSample */
  IndexSample *aSample;    /* Samples of the left-most key */
#endif
};

/*
** Each sample stored in the sqlite_stat3 table is represented in memory 
** using a structure of this type.  See documentation at the top of the
** analyze.c source file for additional information.
*/
struct IndexSample {



  void *p;          /* Pointer to sampled record */

  int n;            /* Size of record in bytes */

  tRowcnt *anEq;    /* Est. number of rows where the key equals this sample */
  tRowcnt *anLt;    /* Est. number of rows where key is less than this sample */
  tRowcnt *anDLt;   /* Est. number of distinct keys less than this sample */
};

/*
** Each token coming out of the lexer is an instance of
** this structure.  Tokens are also used as part of an expression.
**
** Note if Token.z==0 then Token.dyn and Token.n are undefined and

SQLITE_PRIVATE const void *sqlite3ValueText(sqlite3_value*, u8);
SQLITE_PRIVATE int sqlite3ValueBytes(sqlite3_value*, u8);
SQLITE_PRIVATE void sqlite3ValueSetStr(sqlite3_value*, int, const void *,u8, 
                        void(*)(void*));
SQLITE_PRIVATE void sqlite3ValueFree(sqlite3_value*);
SQLITE_PRIVATE sqlite3_value *sqlite3ValueNew(sqlite3 *);
SQLITE_PRIVATE char *sqlite3Utf16to8(sqlite3 *, const void*, int, u8);



SQLITE_PRIVATE int sqlite3ValueFromExpr(sqlite3 *, Expr *, u8, u8, sqlite3_value **);
SQLITE_PRIVATE void sqlite3ValueApplyAffinity(sqlite3_value *, u8, u8);
#ifndef SQLITE_AMALGAMATION
SQLITE_PRIVATE const unsigned char sqlite3OpcodeProperty[];
SQLITE_PRIVATE const unsigned char sqlite3UpperToLower[];
SQLITE_PRIVATE const unsigned char sqlite3CtypeMap[];
SQLITE_PRIVATE const Token sqlite3IntTokens[];

SQLITE_PRIVATE char *sqlite3StrAccumFinish(StrAccum*);
SQLITE_PRIVATE void sqlite3StrAccumReset(StrAccum*);
SQLITE_PRIVATE void sqlite3SelectDestInit(SelectDest*,int,int);
SQLITE_PRIVATE Expr *sqlite3CreateColumnExpr(sqlite3 *, SrcList *, int, int);

SQLITE_PRIVATE void sqlite3BackupRestart(sqlite3_backup *);
SQLITE_PRIVATE void sqlite3BackupUpdate(sqlite3_backup *, Pgno, const u8 *);

#ifdef SQLITE_ENABLE_STAT3_OR_STAT4
SQLITE_PRIVATE void sqlite3AnalyzeFunctions(void);
SQLITE_PRIVATE int sqlite3Stat4ProbeSetValue(Parse*,Index*,UnpackedRecord**,Expr*,u8,int,int*);
SQLITE_PRIVATE void sqlite3Stat4ProbeFree(UnpackedRecord*);
#endif

/*
** The interface to the LEMON-generated parser
*/
SQLITE_PRIVATE void *sqlite3ParserAlloc(void*(*)(size_t));
SQLITE_PRIVATE void sqlite3ParserFree(void*, void(*)(void*));
SQLITE_PRIVATE void sqlite3Parser(void*, int, Token, Parse*);

#endif
#ifdef SQLITE_ENABLE_OVERSIZE_CELL_CHECK
  "ENABLE_OVERSIZE_CELL_CHECK",
#endif
#ifdef SQLITE_ENABLE_RTREE
  "ENABLE_RTREE",
#endif
#if defined(SQLITE_ENABLE_STAT4)
  "ENABLE_STAT4",
#elif defined(SQLITE_ENABLE_STAT3)
  "ENABLE_STAT3",
#endif
#ifdef SQLITE_ENABLE_UNLOCK_NOTIFY
  "ENABLE_UNLOCK_NOTIFY",
#endif
#ifdef SQLITE_ENABLE_UPDATE_DELETE_LIMIT
  "ENABLE_UPDATE_DELETE_LIMIT",

*/
static int sqlite3MemSize(void *p){
  struct MemBlockHdr *pHdr;
  if( !p ){
    return 0;
  }
  pHdr = sqlite3MemsysGetHeader(p);
  return (int)pHdr->iSize;
}

/*
** Initialize the memory allocation subsystem.
*/
static int sqlite3MemInit(void *NotUsed){
  UNUSED_PARAMETER(NotUsed);

** to clear the content of a freed allocation to unpredictable values.
*/
static void randomFill(char *pBuf, int nByte){
  unsigned int x, y, r;
  x = SQLITE_PTR_TO_INT(pBuf);
  y = nByte | 1;
  while( nByte >= 4 ){
    x = (x>>1) ^ (-(int)(x&1) & 0xd0000001);
    y = y*1103515245 + 12345;
    r = x ^ y;
    *(int*)pBuf = r;
    pBuf += 4;
    nByte -= 4;
  }
  while( nByte-- > 0 ){
    x = (x>>1) ^ (-(int)(x&1) & 0xd0000001);
    y = y*1103515245 + 12345;
    r = x ^ y;
    *(pBuf++) = r & 0xff;
  }
}

/*

    pHdr->pNext->pPrev = pHdr->pPrev;
  }else{
    assert( mem.pLast==pHdr );
    mem.pLast = pHdr->pPrev;
  }
  z = (char*)pBt;
  z -= pHdr->nTitle;
  adjustStats((int)pHdr->iSize, -1);
  randomFill(z, sizeof(void*)*pHdr->nBacktraceSlots + sizeof(*pHdr) +
                (int)pHdr->iSize + sizeof(int) + pHdr->nTitle);
  free(z);
  sqlite3_mutex_leave(mem.mutex);  
}

/*
** Change the size of an existing memory allocation.
**

  assert( mem.disallow==0 );
  assert( (nByte & 7)==0 );     /* EV: R-46199-30249 */
  pOldHdr = sqlite3MemsysGetHeader(pPrior);
  pNew = sqlite3MemMalloc(nByte);
  if( pNew ){
    memcpy(pNew, pPrior, nByte<pOldHdr->iSize ? nByte : pOldHdr->iSize);
    if( nByte>pOldHdr->iSize ){
      randomFill(&((char*)pNew)[pOldHdr->iSize], nByte - (int)pOldHdr->iSize);
    }
    sqlite3MemFree(pPrior);
  }
  return pNew;
}

/*

}

SQLITE_PRIVATE void sqlite3MemdebugSync(){
  struct MemBlockHdr *pHdr;
  for(pHdr=mem.pFirst; pHdr; pHdr=pHdr->pNext){
    void **pBt = (void**)pHdr;
    pBt -= pHdr->nBacktraceSlots;
    mem.xBacktrace((int)pHdr->iSize, pHdr->nBacktrace-1, &pBt[1]);
  }
}

/*
** Open the file indicated and write a log of all unfreed memory 
** allocations into that log.
*/

      OSVERSIONINFO sInfo;
      sInfo.dwOSVersionInfoSize = sizeof(sInfo);
      GetVersionEx(&sInfo);
      osType = sInfo.dwPlatformId==VER_PLATFORM_WIN32_NT ? 2 : 1;
    }
    return osType==2;
  }
#endif /* SQLITE_OS_WINCE || SQLITE_OS_WINRT */
#endif

#ifdef SQLITE_DEBUG
/*
** The sqlite3_mutex_held() and sqlite3_mutex_notheld() routine are
** intended for use only inside assert() statements.
*/

};
static int winMutex_isInit = 0;
/* As winMutexInit() and winMutexEnd() are called as part
** of the sqlite3_initialize and sqlite3_shutdown()
** processing, the "interlocked" magic is probably not
** strictly necessary.
*/
static LONG winMutex_lock = 0;

SQLITE_API void sqlite3_win32_sleep(DWORD milliseconds); /* os_win.c */

static int winMutexInit(void){ 
  /* The first to increment to 1 does actual initialization */
  if( InterlockedCompareExchange(&winMutex_lock, 1, 0)==0 ){
    int i;

  assert( (m.flags & MEM_Term)!=0 || db->mallocFailed );
  assert( (m.flags & MEM_Str)!=0 || db->mallocFailed );
  assert( (m.flags & MEM_Dyn)!=0 || db->mallocFailed );
  assert( m.z || db->mallocFailed );
  return m.z;
}



























/*
** zIn is a UTF-16 encoded unicode string at least nChar characters long.
** Return the number of bytes in the first nChar unicode characters
** in pZ.  nChar must be non-negative.
*/
SQLITE_PRIVATE int sqlite3Utf16ByteLen(const void *zIn, int nChar){
  int c;

  unsigned short int ctrlFlags;       /* Behavioral bits.  UNIXFILE_* flags */
  int lastErrno;                      /* The unix errno from last I/O error */
  void *lockingContext;               /* Locking style specific state */
  UnixUnusedFd *pUnused;              /* Pre-allocated UnixUnusedFd */
  const char *zPath;                  /* Name of the file */
  unixShm *pShm;                      /* Shared memory segment information */
  int szChunk;                        /* Configured by FCNTL_CHUNK_SIZE */
#if SQLITE_MAX_MMAP_SIZE>0
  int nFetchOut;                      /* Number of outstanding xFetch refs */
  sqlite3_int64 mmapSize;             /* Usable size of mapping at pMapRegion */
  sqlite3_int64 mmapSizeActual;       /* Actual size of mapping at pMapRegion */
  sqlite3_int64 mmapSizeMax;          /* Configured FCNTL_MMAP_SIZE value */
  void *pMapRegion;                   /* Memory mapped region */
#endif
#ifdef __QNXNTO__
  int sectorSize;                     /* Device sector size */
  int deviceCharacteristics;          /* Precomputed device characteristics */
#endif
#if SQLITE_ENABLE_LOCKING_STYLE
  int openFlags;                      /* The flags specified at open() */
#endif

  { "rmdir",        (sqlite3_syscall_ptr)rmdir,           0 },
#define osRmdir     ((int(*)(const char*))aSyscall[19].pCurrent)

  { "fchown",       (sqlite3_syscall_ptr)posixFchown,     0 },
#define osFchown    ((int(*)(int,uid_t,gid_t))aSyscall[20].pCurrent)

#if !defined(SQLITE_OMIT_WAL) || SQLITE_MAX_MMAP_SIZE>0
  { "mmap",       (sqlite3_syscall_ptr)mmap,     0 },
#define osMmap ((void*(*)(void*,size_t,int,int,int,off_t))aSyscall[21].pCurrent)

  { "munmap",       (sqlite3_syscall_ptr)munmap,          0 },
#define osMunmap ((void*(*)(void*,size_t))aSyscall[22].pCurrent)

#if HAVE_MREMAP
  { "mremap",       (sqlite3_syscall_ptr)mremap,          0 },
#else
  { "mremap",       (sqlite3_syscall_ptr)0,               0 },
#endif
#define osMremap ((void*(*)(void*,size_t,size_t,int,...))aSyscall[23].pCurrent)
#endif

}; /* End of the overrideable system calls */

/*
** This is the xSetSystemCall() method of sqlite3_vfs for all of the
** "unix" VFSes.  Return SQLITE_OK opon successfully updating the
** system call pointer, or SQLITE_NOTFOUND if there is no configurable

** the requested locking level, this routine is a no-op.
*/
static int unixUnlock(sqlite3_file *id, int eFileLock){
  assert( eFileLock==SHARED_LOCK || ((unixFile *)id)->nFetchOut==0 );
  return posixUnlock(id, eFileLock, 0);
}

#if SQLITE_MAX_MMAP_SIZE>0
static int unixMapfile(unixFile *pFd, i64 nByte);
static void unixUnmapfile(unixFile *pFd);
#endif

/*
** This function performs the parts of the "close file" operation 
** common to all locking schemes. It closes the directory and file
** handles, if they are valid, and sets all fields of the unixFile
** structure to 0.
**
** It is *not* necessary to hold the mutex when this routine is called,
** even on VxWorks.  A mutex will be acquired on VxWorks by the
** vxworksReleaseFileId() routine.
*/
static int closeUnixFile(sqlite3_file *id){
  unixFile *pFile = (unixFile*)id;
#if SQLITE_MAX_MMAP_SIZE>0
  unixUnmapfile(pFile);
#endif
  if( pFile->h>=0 ){
    robust_close(pFile, pFile->h, __LINE__);
    pFile->h = -1;
  }
#if OS_VXWORKS
  if( pFile->pId ){
    if( pFile->ctrlFlags & UNIXFILE_DELETE ){

    ** source.
    */
    if( pFile->inNormalWrite && nByte==0 ){
      pFile->transCntrChng = 1;
    }
#endif

#if SQLITE_MAX_MMAP_SIZE>0
    /* If the file was just truncated to a size smaller than the currently
    ** mapped region, reduce the effective mapping size as well. SQLite will
    ** use read() and write() to access data beyond this point from now on.  
    */
    if( nByte<pFile->mmapSize ){
      pFile->mmapSize = nByte;
    }
#endif

    return SQLITE_OK;
  }
}

/*
** Determine the current size of a file in bytes

        if( nWrite!=1 ) return SQLITE_IOERR_WRITE;
        iWrite += nBlk;
      }
#endif
    }
  }

#if SQLITE_MAX_MMAP_SIZE>0
  if( pFile->mmapSizeMax>0 && nByte>pFile->mmapSize ){
    int rc;
    if( pFile->szChunk<=0 ){
      if( robust_ftruncate(pFile->h, nByte) ){
        pFile->lastErrno = errno;
        return unixLogError(SQLITE_IOERR_TRUNCATE, "ftruncate", pFile->zPath);
      }
    }

    rc = unixMapfile(pFile, nByte);
    return rc;
  }
#endif

  return SQLITE_OK;
}

/*
** If *pArg is inititially negative then this is a query.  Set *pArg to
** 1 or 0 depending on whether or not bit mask of pFile->ctrlFlags is set.

      char *zTFile = sqlite3_malloc( pFile->pVfs->mxPathname );
      if( zTFile ){
        unixGetTempname(pFile->pVfs->mxPathname, zTFile);
        *(char**)pArg = zTFile;
      }
      return SQLITE_OK;
    }
#if SQLITE_MAX_MMAP_SIZE>0
    case SQLITE_FCNTL_MMAP_SIZE: {
      i64 newLimit = *(i64*)pArg;
      int rc = SQLITE_OK;
      if( newLimit>sqlite3GlobalConfig.mxMmap ){
        newLimit = sqlite3GlobalConfig.mxMmap;
      }
      *(i64*)pArg = pFile->mmapSizeMax;
      if( newLimit>=0 && newLimit!=pFile->mmapSizeMax && pFile->nFetchOut==0 ){
        pFile->mmapSizeMax = newLimit;
        if( pFile->mmapSize>0 ){
          unixUnmapfile(pFile);
          rc = unixMapfile(pFile, -1);
        }
      }
      return rc;
    }
#endif
#ifdef SQLITE_DEBUG
    /* The pager calls this method to signal that it has done
    ** a rollback and that the database is therefore unchanged and
    ** it hence it is OK for the transaction change counter to be
    ** unchanged.
    */
    case SQLITE_FCNTL_DB_UNCHANGED: {

#else
# define unixShmMap     0
# define unixShmLock    0
# define unixShmBarrier 0
# define unixShmUnmap   0
#endif /* #ifndef SQLITE_OMIT_WAL */

#if SQLITE_MAX_MMAP_SIZE>0
/*
** If it is currently memory mapped, unmap file pFd.
*/
static void unixUnmapfile(unixFile *pFd){
  assert( pFd->nFetchOut==0 );

  if( pFd->pMapRegion ){
    osMunmap(pFd->pMapRegion, pFd->mmapSizeActual);
    pFd->pMapRegion = 0;
    pFd->mmapSize = 0;
    pFd->mmapSizeActual = 0;
  }

}


/*
** Return the system page size.
*/
static int unixGetPagesize(void){
#if HAVE_MREMAP
  return 512;
#elif defined(_BSD_SOURCE)
  return getpagesize();
#else
  return (int)sysconf(_SC_PAGESIZE);
#endif
}



/*
** Attempt to set the size of the memory mapping maintained by file 
** descriptor pFd to nNew bytes. Any existing mapping is discarded.
**
** If successful, this function sets the following variables:
**
**       unixFile.pMapRegion

    ** will probably fail too. Fall back to using xRead/xWrite exclusively
    ** in this case.  */
    pFd->mmapSizeMax = 0;
  }
  pFd->pMapRegion = (void *)pNew;
  pFd->mmapSize = pFd->mmapSizeActual = nNew;
}


/*
** Memory map or remap the file opened by file-descriptor pFd (if the file
** is already mapped, the existing mapping is replaced by the new). Or, if 
** there already exists a mapping for this file, and there are still 
** outstanding xFetch() references to it, this function is a no-op.
**
** If parameter nByte is non-negative, then it is the requested size of 
** the mapping to create. Otherwise, if nByte is less than zero, then the 
** requested size is the size of the file on disk. The actual size of the
** created mapping is either the requested size or the value configured 
** using SQLITE_FCNTL_MMAP_LIMIT, whichever is smaller.
**
** SQLITE_OK is returned if no error occurs (even if the mapping is not
** recreated as a result of outstanding references) or an SQLite error
** code otherwise.
*/
static int unixMapfile(unixFile *pFd, i64 nByte){

  i64 nMap = nByte;
  int rc;

  assert( nMap>=0 || pFd->nFetchOut==0 );
  if( pFd->nFetchOut>0 ) return SQLITE_OK;

  if( nMap<0 ){

  if( nMap!=pFd->mmapSize ){
    if( nMap>0 ){
      unixRemapfile(pFd, nMap);
    }else{
      unixUnmapfile(pFd);
    }
  }


  return SQLITE_OK;
}
#endif /* SQLITE_MAX_MMAP_SIZE>0 */

/*
** If possible, return a pointer to a mapping of file fd starting at offset
** iOff. The mapping must be valid for at least nAmt bytes.
**
** If such a pointer can be obtained, store it in *pp and return SQLITE_OK.
** Or, if one cannot but no error occurs, set *pp to 0 and return SQLITE_OK.

** to inform the VFS layer that, according to POSIX, any existing mapping 
** may now be invalid and should be unmapped.
*/
static int unixUnfetch(sqlite3_file *fd, i64 iOff, void *p){
  unixFile *pFd = (unixFile *)fd;   /* The underlying database file */
  UNUSED_PARAMETER(iOff);

#if SQLITE_MAX_MMAP_SIZE>0
  /* If p==0 (unmap the entire file) then there must be no outstanding 
  ** xFetch references. Or, if p!=0 (meaning it is an xFetch reference),
  ** then there must be at least one outstanding.  */
  assert( (p==0)==(pFd->nFetchOut==0) );

  /* If p!=0, it must match the iOff value. */
  assert( p==0 || p==&((u8 *)pFd->pMapRegion)[iOff] );

  if( p ){
    pFd->nFetchOut--;
  }else{
    unixUnmapfile(pFd);
  }

  assert( pFd->nFetchOut>=0 );
#endif
  return SQLITE_OK;
}

/*
** Here ends the implementation of all sqlite3_file methods.
**
********************** End sqlite3_file Methods *******************************

  assert( zFilename!=0 || (ctrlFlags & UNIXFILE_NOLOCK)!=0 );

  OSTRACE(("OPEN    %-3d %s\n", h, zFilename));
  pNew->h = h;
  pNew->pVfs = pVfs;
  pNew->zPath = zFilename;
  pNew->ctrlFlags = (u8)ctrlFlags;
#if SQLITE_MAX_MMAP_SIZE>0
  pNew->mmapSizeMax = sqlite3GlobalConfig.szMmap;
#endif
  if( sqlite3_uri_boolean(((ctrlFlags & UNIXFILE_URI) ? zFilename : 0),
                           "psow", SQLITE_POWERSAFE_OVERWRITE) ){
    pNew->ctrlFlags |= UNIXFILE_PSOW;
  }
  if( strcmp(pVfs->zName,"unix-excl")==0 ){
    pNew->ctrlFlags |= UNIXFILE_EXCL;
  }

/************** Continuing where we left off in os_win.c *********************/

/*
** Compiling and using WAL mode requires several APIs that are only
** available in Windows platforms based on the NT kernel.
*/
#if !SQLITE_OS_WINNT && !defined(SQLITE_OMIT_WAL)
#  error "WAL mode requires support from the Windows NT kernel, compile\
 with SQLITE_OMIT_WAL."
#endif

/*
** Are most of the Win32 ANSI APIs available (i.e. with certain exceptions
** based on the sub-platform)?
*/
#if !SQLITE_OS_WINCE && !SQLITE_OS_WINRT
#  define SQLITE_WIN32_HAS_ANSI
#endif

/*
** Are most of the Win32 Unicode APIs available (i.e. with certain exceptions
** based on the sub-platform)?
*/
#if SQLITE_OS_WINCE || SQLITE_OS_WINNT || SQLITE_OS_WINRT
#  define SQLITE_WIN32_HAS_WIDE
#endif

/*
** Maximum pathname length (in chars) for Win32.  This should normally be
** MAX_PATH.
*/
#ifndef SQLITE_WIN32_MAX_PATH_CHARS
#  define SQLITE_WIN32_MAX_PATH_CHARS   (MAX_PATH)
#endif

/*
** Maximum pathname length (in chars) for WinNT.  This should normally be
** 32767.
*/
#ifndef SQLITE_WINNT_MAX_PATH_CHARS
#  define SQLITE_WINNT_MAX_PATH_CHARS   (32767)
#endif

/*
** Maximum pathname length (in bytes) for Win32.  The MAX_PATH macro is in
** characters, so we allocate 3 bytes per character assuming worst-case of
** 4-bytes-per-character for UTF8.
*/
#ifndef SQLITE_WIN32_MAX_PATH_BYTES
#  define SQLITE_WIN32_MAX_PATH_BYTES   (SQLITE_WIN32_MAX_PATH_CHARS*4)
#endif

/*
** Maximum pathname length (in bytes) for WinNT.  This should normally be
** 32767 * sizeof(WCHAR).
*/
#ifndef SQLITE_WINNT_MAX_PATH_BYTES
#  define SQLITE_WINNT_MAX_PATH_BYTES   \
                            (sizeof(WCHAR) * SQLITE_WINNT_MAX_PATH_CHARS)
#endif

/*
** Maximum error message length (in chars) for WinRT.
*/
#ifndef SQLITE_WIN32_MAX_ERRMSG_CHARS
#  define SQLITE_WIN32_MAX_ERRMSG_CHARS (1024)
#endif

/*
** Returns non-zero if the character should be treated as a directory
** separator.
*/
#ifndef winIsDirSep
#  define winIsDirSep(a)                (((a) == '/') || ((a) == '\\'))
#endif

/*
** Returns the string that should be used as the directory separator.
*/
#ifndef winGetDirDep
#  ifdef __CYGWIN__
#    define winGetDirDep()              "/"
#  else
#    define winGetDirDep()              "\\"
#  endif
#endif

/*
** Do we need to manually define the Win32 file mapping APIs for use with WAL
** mode (e.g. these APIs are available in the Windows CE SDK; however, they
** are not present in the header file)?
*/
#if SQLITE_WIN32_FILEMAPPING_API && !defined(SQLITE_OMIT_WAL)
/*

** the LockFileEx() API.  But we can still statically link against that
** API as long as we don't call it when running Win95/98/ME.  A call to
** this routine is used to determine if the host is Win95/98/ME or
** WinNT/2K/XP so that we will know whether or not we can safely call
** the LockFileEx() API.
*/
#if SQLITE_OS_WINCE || SQLITE_OS_WINRT
# define osIsNT()  (1)
#elif !defined(SQLITE_WIN32_HAS_WIDE)
# define osIsNT()  (0)
#else
  static int osIsNT(void){
    if( sqlite3_os_type==0 ){
      OSVERSIONINFOA sInfo;
      sInfo.dwOSVersionInfoSize = sizeof(sInfo);
      osGetVersionExA(&sInfo);
      sqlite3_os_type = sInfo.dwPlatformId==VER_PLATFORM_WIN32_NT ? 2 : 1;
    }
    return sqlite3_os_type==2;

#endif /* SQLITE_WIN32_MALLOC */

/*
** Convert a UTF-8 string to Microsoft Unicode (UTF-16?). 
**
** Space to hold the returned string is obtained from malloc.
*/
static LPWSTR winUtf8ToUnicode(const char *zFilename){
  int nChar;
  LPWSTR zWideFilename;

  nChar = osMultiByteToWideChar(CP_UTF8, 0, zFilename, -1, NULL, 0);
  if( nChar==0 ){
    return 0;
  }

  return zWideFilename;
}

/*
** Convert Microsoft Unicode to UTF-8.  Space to hold the returned string is
** obtained from sqlite3_malloc().
*/
static char *winUnicodeToUtf8(LPCWSTR zWideFilename){
  int nByte;
  char *zFilename;

  nByte = osWideCharToMultiByte(CP_UTF8, 0, zWideFilename, -1, 0, 0, 0, 0);
  if( nByte == 0 ){
    return 0;
  }

/*
** Convert an ANSI string to Microsoft Unicode, based on the
** current codepage settings for file apis.
** 
** Space to hold the returned string is obtained
** from sqlite3_malloc.
*/
static LPWSTR winMbcsToUnicode(const char *zFilename){
  int nByte;
  LPWSTR zMbcsFilename;
  int codepage = osAreFileApisANSI() ? CP_ACP : CP_OEMCP;

  nByte = osMultiByteToWideChar(codepage, 0, zFilename, -1, NULL,
                                0)*sizeof(WCHAR);
  if( nByte==0 ){

/*
** Convert Microsoft Unicode to multi-byte character string, based on the
** user's ANSI codepage.
**
** Space to hold the returned string is obtained from
** sqlite3_malloc().
*/
static char *winUnicodeToMbcs(LPCWSTR zWideFilename){
  int nByte;
  char *zFilename;
  int codepage = osAreFileApisANSI() ? CP_ACP : CP_OEMCP;

  nByte = osWideCharToMultiByte(codepage, 0, zWideFilename, -1, 0, 0, 0, 0);
  if( nByte == 0 ){
    return 0;

** Convert multibyte character string to UTF-8.  Space to hold the
** returned string is obtained from sqlite3_malloc().
*/
SQLITE_API char *sqlite3_win32_mbcs_to_utf8(const char *zFilename){
  char *zFilenameUtf8;
  LPWSTR zTmpWide;

  zTmpWide = winMbcsToUnicode(zFilename);
  if( zTmpWide==0 ){
    return 0;
  }
  zFilenameUtf8 = winUnicodeToUtf8(zTmpWide);
  sqlite3_free(zTmpWide);
  return zFilenameUtf8;
}

/*
** Convert UTF-8 to multibyte character string.  Space to hold the 
** returned string is obtained from sqlite3_malloc().
*/
SQLITE_API char *sqlite3_win32_utf8_to_mbcs(const char *zFilename){
  char *zFilenameMbcs;
  LPWSTR zTmpWide;

  zTmpWide = winUtf8ToUnicode(zFilename);
  if( zTmpWide==0 ){
    return 0;
  }
  zFilenameMbcs = winUnicodeToMbcs(zTmpWide);
  sqlite3_free(zTmpWide);
  return zFilenameMbcs;
}

/*
** This function sets the data directory or the temporary directory based on
** the provided arguments.  The type argument must be 1 in order to set the

  assert( !ppDirectory || type==SQLITE_WIN32_DATA_DIRECTORY_TYPE
          || type==SQLITE_WIN32_TEMP_DIRECTORY_TYPE
  );
  assert( !ppDirectory || sqlite3MemdebugHasType(*ppDirectory, MEMTYPE_HEAP) );
  if( ppDirectory ){
    char *zValueUtf8 = 0;
    if( zValue && zValue[0] ){
      zValueUtf8 = winUnicodeToUtf8(zValue);
      if ( zValueUtf8==0 ){
        return SQLITE_NOMEM;
      }
    }
    sqlite3_free(*ppDirectory);
    *ppDirectory = zValueUtf8;
    return SQLITE_OK;
  }
  return SQLITE_ERROR;
}

/*
** The return value of winGetLastErrorMsg
** is zero if the error message fits in the buffer, or non-zero
** otherwise (if the message was truncated).
*/
static int winGetLastErrorMsg(DWORD lastErrno, int nBuf, char *zBuf){
  /* FormatMessage returns 0 on failure.  Otherwise it
  ** returns the number of TCHARs written to the output
  ** buffer, excluding the terminating null char.
  */
  DWORD dwLen = 0;
  char *zOut = 0;

  if( osIsNT() ){
#if SQLITE_OS_WINRT
    WCHAR zTempWide[SQLITE_WIN32_MAX_ERRMSG_CHARS+1];
    dwLen = osFormatMessageW(FORMAT_MESSAGE_FROM_SYSTEM |
                             FORMAT_MESSAGE_IGNORE_INSERTS,
                             NULL,
                             lastErrno,
                             0,
                             zTempWide,
                             SQLITE_WIN32_MAX_ERRMSG_CHARS,
                             0);
#else
    LPWSTR zTempWide = NULL;
    dwLen = osFormatMessageW(FORMAT_MESSAGE_ALLOCATE_BUFFER |
                             FORMAT_MESSAGE_FROM_SYSTEM |
                             FORMAT_MESSAGE_IGNORE_INSERTS,
                             NULL,
                             lastErrno,
                             0,
                             (LPWSTR) &zTempWide,
                             0,
                             0);
#endif
    if( dwLen > 0 ){
      /* allocate a buffer and convert to UTF8 */
      sqlite3BeginBenignMalloc();
      zOut = winUnicodeToUtf8(zTempWide);
      sqlite3EndBenignMalloc();
#if !SQLITE_OS_WINRT
      /* free the system buffer allocated by FormatMessage */
      osLocalFree(zTempWide);
#endif
    }
  }

  const char *zPath,              /* File path associated with error */
  int iLine                       /* Source line number where error occurred */
){
  char zMsg[500];                 /* Human readable error text */
  int i;                          /* Loop counter */

  zMsg[0] = 0;
  winGetLastErrorMsg(lastErrno, sizeof(zMsg), zMsg);
  assert( errcode!=SQLITE_OK );
  if( zPath==0 ) zPath = "";
  for(i=0; zMsg[i] && zMsg[i]!='\r' && zMsg[i]!='\n'; i++){}
  zMsg[i] = 0;
  sqlite3_log(errcode,
      "os_win.c:%d: (%lu) %s(%s) - %s",
      iLine, lastErrno, zFunc, zPath, zMsg

*/
#ifndef SQLITE_WIN32_IOERR_RETRY
# define SQLITE_WIN32_IOERR_RETRY 10
#endif
#ifndef SQLITE_WIN32_IOERR_RETRY_DELAY
# define SQLITE_WIN32_IOERR_RETRY_DELAY 25
#endif
static int winIoerrRetry = SQLITE_WIN32_IOERR_RETRY;
static int winIoerrRetryDelay = SQLITE_WIN32_IOERR_RETRY_DELAY;

/*
** If a ReadFile() or WriteFile() error occurs, invoke this routine
** to see if it should be retried.  Return TRUE to retry.  Return FALSE
** to give up with an error.
*/
static int winRetryIoerr(int *pnRetry, DWORD *pError){
  DWORD e = osGetLastError();
  if( *pnRetry>=winIoerrRetry ){
    if( pError ){
      *pError = e;
    }
    return 0;
  }
  if( e==ERROR_ACCESS_DENIED ||
      e==ERROR_LOCK_VIOLATION ||
      e==ERROR_SHARING_VIOLATION ){
    sqlite3_win32_sleep(winIoerrRetryDelay*(1+*pnRetry));
    ++*pnRetry;
    return 1;
  }
  if( pError ){
    *pError = e;
  }
  return 0;
}

/*
** Log a I/O error retry episode.
*/
static void winLogIoerr(int nRetry){
  if( nRetry ){
    sqlite3_log(SQLITE_IOERR, 
      "delayed %dms for lock/sharing conflict",
      winIoerrRetryDelay*nRetry*(nRetry+1)/2
    );
  }
}

#if SQLITE_OS_WINCE
/*************************************************************************
** This section contains code for WinCE only.

static int winceCreateLock(const char *zFilename, winFile *pFile){
  LPWSTR zTok;
  LPWSTR zName;
  DWORD lastErrno;
  BOOL bLogged = FALSE;
  BOOL bInit = TRUE;

  zName = winUtf8ToUnicode(zFilename);
  if( zName==0 ){
    /* out of memory */
    return SQLITE_IOERR_NOMEM;
  }

  /* Initialize the local lockdata */
  memset(&pFile->local, 0, sizeof(pFile->local));

  /*
  ** NOTE: Windows CE is handled differently here due its lack of the Win32
  **       API LockFile.
  */
  return winceLockFile(phFile, offsetLow, offsetHigh,
                       numBytesLow, numBytesHigh);
#else
  if( osIsNT() ){
    OVERLAPPED ovlp;
    memset(&ovlp, 0, sizeof(OVERLAPPED));
    ovlp.Offset = offsetLow;
    ovlp.OffsetHigh = offsetHigh;
    return osLockFileEx(*phFile, flags, 0, numBytesLow, numBytesHigh, &ovlp);
  }else{
    return osLockFile(*phFile, offsetLow, offsetHigh, numBytesLow,

  /*
  ** NOTE: Windows CE is handled differently here due its lack of the Win32
  **       API UnlockFile.
  */
  return winceUnlockFile(phFile, offsetLow, offsetHigh,
                         numBytesLow, numBytesHigh);
#else
  if( osIsNT() ){
    OVERLAPPED ovlp;
    memset(&ovlp, 0, sizeof(OVERLAPPED));
    ovlp.Offset = offsetLow;
    ovlp.OffsetHigh = offsetHigh;
    return osUnlockFileEx(*phFile, 0, numBytesLow, numBytesHigh, &ovlp);
  }else{
    return osUnlockFile(*phFile, offsetLow, offsetHigh, numBytesLow,

#endif

/*
** Move the current position of the file handle passed as the first 
** argument to offset iOffset within the file. If successful, return 0. 
** Otherwise, set pFile->lastErrno and return non-zero.
*/
static int winSeekFile(winFile *pFile, sqlite3_int64 iOffset){
#if !SQLITE_OS_WINRT
  LONG upperBits;                 /* Most sig. 32 bits of new offset */
  LONG lowerBits;                 /* Least sig. 32 bits of new offset */
  DWORD dwRet;                    /* Value returned by SetFilePointer() */
  DWORD lastErrno;                /* Value returned by GetLastError() */

  OSTRACE(("SEEK file=%p, offset=%lld\n", pFile->h, iOffset));

  */
  dwRet = osSetFilePointer(pFile->h, lowerBits, &upperBits, FILE_BEGIN);

  if( (dwRet==INVALID_SET_FILE_POINTER
      && ((lastErrno = osGetLastError())!=NO_ERROR)) ){
    pFile->lastErrno = lastErrno;
    winLogError(SQLITE_IOERR_SEEK, pFile->lastErrno,
             "winSeekFile", pFile->zPath);
    OSTRACE(("SEEK file=%p, rc=SQLITE_IOERR_SEEK\n", pFile->h));
    return 1;
  }

  OSTRACE(("SEEK file=%p, rc=SQLITE_OK\n", pFile->h));
  return 0;
#else
  /*
  ** Same as above, except that this implementation works for WinRT.
  */

  LARGE_INTEGER x;                /* The new offset */
  BOOL bRet;                      /* Value returned by SetFilePointerEx() */

  x.QuadPart = iOffset;
  bRet = osSetFilePointerEx(pFile->h, x, 0, FILE_BEGIN);

  if(!bRet){
    pFile->lastErrno = osGetLastError();
    winLogError(SQLITE_IOERR_SEEK, pFile->lastErrno,
             "winSeekFile", pFile->zPath);
    OSTRACE(("SEEK file=%p, rc=SQLITE_IOERR_SEEK\n", pFile->h));
    return 1;
  }

  OSTRACE(("SEEK file=%p, rc=SQLITE_OK\n", pFile->h));
  return 0;
#endif

      amt -= nCopy;
      offset += nCopy;
    }
  }
#endif

#if SQLITE_OS_WINCE
  if( winSeekFile(pFile, offset) ){
    OSTRACE(("READ file=%p, rc=SQLITE_FULL\n", pFile->h));
    return SQLITE_FULL;
  }
  while( !osReadFile(pFile->h, pBuf, amt, &nRead, 0) ){
#else
  memset(&overlapped, 0, sizeof(OVERLAPPED));
  overlapped.Offset = (LONG)(offset & 0xffffffff);
  overlapped.OffsetHigh = (LONG)((offset>>32) & 0x7fffffff);
  while( !osReadFile(pFile->h, pBuf, amt, &nRead, &overlapped) &&
         osGetLastError()!=ERROR_HANDLE_EOF ){
#endif
    DWORD lastErrno;
    if( winRetryIoerr(&nRetry, &lastErrno) ) continue;
    pFile->lastErrno = lastErrno;
    OSTRACE(("READ file=%p, rc=SQLITE_IOERR_READ\n", pFile->h));
    return winLogError(SQLITE_IOERR_READ, pFile->lastErrno,
             "winRead", pFile->zPath);
  }
  winLogIoerr(nRetry);
  if( nRead<(DWORD)amt ){
    /* Unread parts of the buffer must be zero-filled */
    memset(&((char*)pBuf)[nRead], 0, amt-nRead);
    OSTRACE(("READ file=%p, rc=SQLITE_IOERR_SHORT_READ\n", pFile->h));
    return SQLITE_IOERR_SHORT_READ;
  }

      amt -= nCopy;
      offset += nCopy;
    }
  }
#endif

#if SQLITE_OS_WINCE
  rc = winSeekFile(pFile, offset);
  if( rc==0 ){
#else
  {
#endif
#if !SQLITE_OS_WINCE
    OVERLAPPED overlapped;        /* The offset for WriteFile. */
#endif

    while( nRem>0 ){
#if SQLITE_OS_WINCE
      if( !osWriteFile(pFile->h, aRem, nRem, &nWrite, 0) ){
#else
      if( !osWriteFile(pFile->h, aRem, nRem, &nWrite, &overlapped) ){
#endif
        if( winRetryIoerr(&nRetry, &lastErrno) ) continue;
        break;
      }
      assert( nWrite==0 || nWrite<=(DWORD)nRem );
      if( nWrite==0 || nWrite>(DWORD)nRem ){
        lastErrno = osGetLastError();
        break;
      }

      OSTRACE(("WRITE file=%p, rc=SQLITE_FULL\n", pFile->h));
      return SQLITE_FULL;
    }
    OSTRACE(("WRITE file=%p, rc=SQLITE_IOERR_WRITE\n", pFile->h));
    return winLogError(SQLITE_IOERR_WRITE, pFile->lastErrno,
             "winWrite", pFile->zPath);
  }else{
    winLogIoerr(nRetry);
  }
  OSTRACE(("WRITE file=%p, rc=SQLITE_OK\n", pFile->h));
  return SQLITE_OK;
}

/*
** Truncate an open file to a specified size

  ** size).
  */
  if( pFile->szChunk>0 ){
    nByte = ((nByte + pFile->szChunk - 1)/pFile->szChunk) * pFile->szChunk;
  }

  /* SetEndOfFile() returns non-zero when successful, or zero when it fails. */
  if( winSeekFile(pFile, nByte) ){
    rc = winLogError(SQLITE_IOERR_TRUNCATE, pFile->lastErrno,
                     "winTruncate1", pFile->zPath);
  }else if( 0==osSetEndOfFile(pFile->h) &&
            ((lastErrno = osGetLastError())!=ERROR_USER_MAPPED_FILE) ){
    pFile->lastErrno = lastErrno;
    rc = winLogError(SQLITE_IOERR_TRUNCATE, pFile->lastErrno,
                     "winTruncate2", pFile->zPath);

  sqlite3_sync_count++;
#endif

  /* If we compiled with the SQLITE_NO_SYNC flag, then syncing is a
  ** no-op
  */
#ifdef SQLITE_NO_SYNC
  OSTRACE(("SYNC-NOP file=%p, rc=SQLITE_OK\n", pFile->h));
  return SQLITE_OK;
#else
  rc = osFlushFileBuffers(pFile->h);
  SimulateIOError( rc=FALSE );
  if( rc ){
    OSTRACE(("SYNC file=%p, rc=SQLITE_OK\n", pFile->h));
    return SQLITE_OK;

#endif

/*
** Acquire a reader lock.
** Different API routines are called depending on whether or not this
** is Win9x or WinNT.
*/
static int winGetReadLock(winFile *pFile){
  int res;
  OSTRACE(("READ-LOCK file=%p, lock=%d\n", pFile->h, pFile->locktype));
  if( osIsNT() ){
#if SQLITE_OS_WINCE
    /*
    ** NOTE: Windows CE is handled differently here due its lack of the Win32
    **       API LockFileEx.
    */
    res = winceLockFile(&pFile->h, SHARED_FIRST, 0, 1, 0);
#else

  OSTRACE(("READ-LOCK file=%p, rc=%s\n", pFile->h, sqlite3ErrName(res)));
  return res;
}

/*
** Undo a readlock
*/
static int winUnlockReadLock(winFile *pFile){
  int res;
  DWORD lastErrno;
  OSTRACE(("READ-UNLOCK file=%p, lock=%d\n", pFile->h, pFile->locktype));
  if( osIsNT() ){
    res = winUnlockFile(&pFile->h, SHARED_FIRST, 0, SHARED_SIZE, 0);
  }
#ifdef SQLITE_WIN32_HAS_ANSI
  else{
    res = winUnlockFile(&pFile->h, SHARED_FIRST+pFile->sharedLockByte, 0, 1, 0);
  }
#endif
  if( res==0 && ((lastErrno = osGetLastError())!=ERROR_NOT_LOCKED) ){
    pFile->lastErrno = lastErrno;
    winLogError(SQLITE_IOERR_UNLOCK, pFile->lastErrno,
             "winUnlockReadLock", pFile->zPath);
  }
  OSTRACE(("READ-UNLOCK file=%p, rc=%s\n", pFile->h, sqlite3ErrName(res)));
  return res;
}

/*
** Lock the file with the lock specified by parameter locktype - one

    }
  }

  /* Acquire a shared lock
  */
  if( locktype==SHARED_LOCK && res ){
    assert( pFile->locktype==NO_LOCK );
    res = winGetReadLock(pFile);
    if( res ){
      newLocktype = SHARED_LOCK;
    }else{
      lastErrno = osGetLastError();
    }
  }

    gotPendingLock = 0;
  }

  /* Acquire an EXCLUSIVE lock
  */
  if( locktype==EXCLUSIVE_LOCK && res ){
    assert( pFile->locktype>=SHARED_LOCK );
    res = winUnlockReadLock(pFile);
    res = winLockFile(&pFile->h, SQLITE_LOCKFILE_FLAGS, SHARED_FIRST, 0,
                      SHARED_SIZE, 0);
    if( res ){
      newLocktype = EXCLUSIVE_LOCK;
    }else{
      lastErrno = osGetLastError();
      winGetReadLock(pFile);
    }
  }

  /* If we are holding a PENDING lock that ought to be released, then
  ** release it now.
  */
  if( gotPendingLock && locktype==SHARED_LOCK ){
    winUnlockFile(&pFile->h, PENDING_BYTE, 0, 1, 0);
  }

  /* Update the state of the lock has held in the file descriptor then
  ** return the appropriate result code.
  */
  if( res ){
    rc = SQLITE_OK;
  }else{


    pFile->lastErrno = lastErrno;
    rc = SQLITE_BUSY;
    OSTRACE(("LOCK-FAIL file=%p, wanted=%d, got=%d\n",
             pFile->h, locktype, newLocktype));
  }
  pFile->locktype = (u8)newLocktype;
  OSTRACE(("LOCK file=%p, lock=%d, rc=%s\n",
           pFile->h, pFile->locktype, sqlite3ErrName(rc)));
  return rc;
}

  assert( pFile!=0 );
  assert( locktype<=SHARED_LOCK );
  OSTRACE(("UNLOCK file=%p, oldLock=%d(%d), newLock=%d\n",
           pFile->h, pFile->locktype, pFile->sharedLockByte, locktype));
  type = pFile->locktype;
  if( type>=EXCLUSIVE_LOCK ){
    winUnlockFile(&pFile->h, SHARED_FIRST, 0, SHARED_SIZE, 0);
    if( locktype==SHARED_LOCK && !winGetReadLock(pFile) ){
      /* This should never happen.  We should always be able to
      ** reacquire the read lock */
      rc = winLogError(SQLITE_IOERR_UNLOCK, osGetLastError(),
               "winUnlock", pFile->zPath);
    }
  }
  if( type>=RESERVED_LOCK ){
    winUnlockFile(&pFile->h, RESERVED_BYTE, 0, 1, 0);
  }
  if( locktype==NO_LOCK && type>=SHARED_LOCK ){
    winUnlockReadLock(pFile);
  }
  if( type>=PENDING_LOCK ){
    winUnlockFile(&pFile->h, PENDING_BYTE, 0, 1, 0);
  }
  pFile->locktype = (u8)locktype;
  OSTRACE(("UNLOCK file=%p, lock=%d, rc=%s\n",
           pFile->h, pFile->locktype, sqlite3ErrName(rc)));

    pFile->ctrlFlags &= ~mask;
  }else{
    pFile->ctrlFlags |= mask;
  }
}

/* Forward declaration */
static int winGetTempname(sqlite3_vfs *, char **);
#if SQLITE_MAX_MMAP_SIZE>0
static int winMapfile(winFile*, sqlite3_int64);
#endif

/*
** Control and query of the open file handle.
*/

      *(char**)pArg = sqlite3_mprintf("win32");
      OSTRACE(("FCNTL file=%p, rc=SQLITE_OK\n", pFile->h));
      return SQLITE_OK;
    }
    case SQLITE_FCNTL_WIN32_AV_RETRY: {
      int *a = (int*)pArg;
      if( a[0]>0 ){
        winIoerrRetry = a[0];
      }else{
        a[0] = winIoerrRetry;
      }
      if( a[1]>0 ){
        winIoerrRetryDelay = a[1];
      }else{
        a[1] = winIoerrRetryDelay;
      }
      OSTRACE(("FCNTL file=%p, rc=SQLITE_OK\n", pFile->h));
      return SQLITE_OK;
    }
    case SQLITE_FCNTL_TEMPFILENAME: {
      char *zTFile = 0;

      int rc = winGetTempname(pFile->pVfs, &zTFile);
      if( rc==SQLITE_OK ){
        *(char**)pArg = zTFile;
      }
      OSTRACE(("FCNTL file=%p, rc=%d\n", pFile->h, rc));
      return rc;
    }
#if SQLITE_MAX_MMAP_SIZE>0
    case SQLITE_FCNTL_MMAP_SIZE: {
      i64 newLimit = *(i64*)pArg;
      int rc = SQLITE_OK;
      if( newLimit>sqlite3GlobalConfig.mxMmap ){
        newLimit = sqlite3GlobalConfig.mxMmap;

/*
** Convert a UTF-8 filename into whatever form the underlying
** operating system wants filenames in.  Space to hold the result
** is obtained from malloc and must be freed by the calling
** function.
*/
static void *winConvertUtf8Filename(const char *zFilename){
  void *zConverted = 0;
  if( osIsNT() ){
    zConverted = winUtf8ToUnicode(zFilename);
  }
#ifdef SQLITE_WIN32_HAS_ANSI
  else{
    zConverted = sqlite3_win32_utf8_to_mbcs(zFilename);
  }
#endif
  /* caller will handle out of memory */
  return zConverted;
}

/*
** This function returns non-zero if the specified UTF-8 string buffer
** ends with a directory separator character.

*/
static int winEndsInDirSep(char *zBuf){
  if( zBuf ){
    int nLen = sqlite3Strlen30(zBuf);
    return nLen>0 && winIsDirSep(zBuf[nLen-1]);
  }
  return 0;
}

/*
** Create a temporary file name and store the resulting pointer into pzBuf.

** The pointer returned in pzBuf must be freed via sqlite3_free().
*/
static int winGetTempname(sqlite3_vfs *pVfs, char **pzBuf){
  static char zChars[] =
    "abcdefghijklmnopqrstuvwxyz"
    "ABCDEFGHIJKLMNOPQRSTUVWXYZ"
    "0123456789";
  size_t i, j;
  int nBuf, nLen;
  char *zBuf;

  /* It's odd to simulate an io-error here, but really this is just
  ** using the io-error infrastructure to test that SQLite handles this
  ** function failing. 
  */
  SimulateIOError( return SQLITE_IOERR );

  /* Allocate a temporary buffer to store the fully qualified file
  ** name for the temporary file.  If this fails, we cannot continue.
  */
  nBuf = pVfs->mxPathname;
  zBuf = sqlite3MallocZero( nBuf+2 );
  if( !zBuf ){
    OSTRACE(("TEMP-FILENAME rc=SQLITE_IOERR_NOMEM\n"));
    return SQLITE_IOERR_NOMEM;
  }

  /* Figure out the effective temporary directory.  First, check if one
  ** has been explicitly set by the application; otherwise, use the one
  ** configured by the operating system.
  */
  assert( nBuf>30 );
  if( sqlite3_temp_directory ){
    sqlite3_snprintf(nBuf-30, zBuf, "%s%s", sqlite3_temp_directory,
                     winEndsInDirSep(sqlite3_temp_directory) ? "" :
                     winGetDirDep());
  }
#if !SQLITE_OS_WINRT
  else if( osIsNT() ){
    char *zMulti;
    LPWSTR zWidePath = sqlite3MallocZero( nBuf*sizeof(WCHAR) );
    if( !zWidePath ){
      sqlite3_free(zBuf);
      OSTRACE(("TEMP-FILENAME rc=SQLITE_IOERR_NOMEM\n"));
      return SQLITE_IOERR_NOMEM;
    }
    if( osGetTempPathW(nBuf, zWidePath)==0 ){
      sqlite3_free(zWidePath);
      sqlite3_free(zBuf);
      OSTRACE(("TEMP-FILENAME rc=SQLITE_IOERR_GETTEMPPATH\n"));
      return SQLITE_IOERR_GETTEMPPATH;
    }
    zMulti = winUnicodeToUtf8(zWidePath);
    if( zMulti ){
      sqlite3_snprintf(nBuf-30, zBuf, "%s", zMulti);
      sqlite3_free(zMulti);
      sqlite3_free(zWidePath);
    }else{
      sqlite3_free(zWidePath);
      sqlite3_free(zBuf);
      OSTRACE(("TEMP-FILENAME rc=SQLITE_IOERR_NOMEM\n"));
      return SQLITE_IOERR_NOMEM;
    }
  }
#ifdef SQLITE_WIN32_HAS_ANSI
  else{
    char *zUtf8;
    char *zMbcsPath = sqlite3MallocZero( nBuf );
    if( !zMbcsPath ){
      sqlite3_free(zBuf);
      OSTRACE(("TEMP-FILENAME rc=SQLITE_IOERR_NOMEM\n"));
      return SQLITE_IOERR_NOMEM;
    }
    if( osGetTempPathA(nBuf, zMbcsPath)==0 ){
      sqlite3_free(zBuf);
      OSTRACE(("TEMP-FILENAME rc=SQLITE_IOERR_GETTEMPPATH\n"));
      return SQLITE_IOERR_GETTEMPPATH;
    }
    zUtf8 = sqlite3_win32_mbcs_to_utf8(zMbcsPath);
    if( zUtf8 ){
      sqlite3_snprintf(nBuf-30, zBuf, "%s", zUtf8);
      sqlite3_free(zUtf8);
    }else{
      sqlite3_free(zBuf);
      OSTRACE(("TEMP-FILENAME rc=SQLITE_IOERR_NOMEM\n"));
      return SQLITE_IOERR_NOMEM;
    }
  }








#endif /* SQLITE_WIN32_HAS_ANSI */








#endif /* !SQLITE_OS_WINRT */

  /* Check that the output buffer is large enough for the temporary file 
  ** name. If it is not, return SQLITE_ERROR.
  */
  nLen = sqlite3Strlen30(zBuf);

  if( (nLen + sqlite3Strlen30(SQLITE_TEMP_FILE_PREFIX) + 18) >= nBuf ){
    sqlite3_free(zBuf);
    OSTRACE(("TEMP-FILENAME rc=SQLITE_ERROR\n"));
    return SQLITE_ERROR;
  }

  sqlite3_snprintf(nBuf-18-nLen, zBuf+nLen, SQLITE_TEMP_FILE_PREFIX);





  j = sqlite3Strlen30(zBuf);
  sqlite3_randomness(15, &zBuf[j]);
  for(i=0; i<15; i++, j++){
    zBuf[j] = (char)zChars[ ((unsigned char)zBuf[j])%(sizeof(zChars)-1) ];
  }
  zBuf[j] = 0;
  zBuf[j+1] = 0;
  *pzBuf = zBuf;

  OSTRACE(("TEMP-FILENAME name=%s, rc=SQLITE_OK\n", zBuf));
  return SQLITE_OK;
}

/*
** Return TRUE if the named file is really a directory.  Return false if
** it is something other than a directory, or if there is any kind of memory
** allocation failure.
*/
static int winIsDir(const void *zConverted){
  DWORD attr;
  int rc = 0;
  DWORD lastErrno;

  if( osIsNT() ){
    int cnt = 0;
    WIN32_FILE_ATTRIBUTE_DATA sAttrData;
    memset(&sAttrData, 0, sizeof(sAttrData));
    while( !(rc = osGetFileAttributesExW((LPCWSTR)zConverted,
                             GetFileExInfoStandard,
                             &sAttrData)) && winRetryIoerr(&cnt, &lastErrno) ){}
    if( !rc ){
      return 0; /* Invalid name? */
    }
    attr = sAttrData.dwFileAttributes;
#if SQLITE_OS_WINCE==0
  }else{
    attr = osGetFileAttributesA((char*)zConverted);
#endif
  }
  return (attr!=INVALID_FILE_ATTRIBUTES) && (attr&FILE_ATTRIBUTE_DIRECTORY);
}

/*
** Open a file.
*/
static int winOpen(
  sqlite3_vfs *pVfs,        /* Used to get maximum path name length */
  const char *zName,        /* Name of the file (UTF-8) */
  sqlite3_file *id,         /* Write the SQLite file handle here */
  int flags,                /* Open mode flags */
  int *pOutFlags            /* Status return flags */
){
  HANDLE h;
  DWORD lastErrno;

  void *zConverted;              /* Filename in OS encoding */
  const char *zUtf8Name = zName; /* Filename in UTF-8 encoding */
  int cnt = 0;

  /* If argument zPath is a NULL pointer, this function is required to open
  ** a temporary file. Use this buffer to store the file name in.
  */
  char *zTmpname = 0; /* For temporary filename, if necessary. */

  int rc = SQLITE_OK;            /* Function Return Code */
#if !defined(NDEBUG) || SQLITE_OS_WINCE
  int eType = flags&0xFFFFFF00;  /* Type of file to open */
#endif

  int isExclusive  = (flags & SQLITE_OPEN_EXCLUSIVE);

  );

  assert( pFile!=0 );
  memset(pFile, 0, sizeof(winFile));
  pFile->h = INVALID_HANDLE_VALUE;

#if SQLITE_OS_WINRT
  if( !zUtf8Name && !sqlite3_temp_directory ){
    sqlite3_log(SQLITE_ERROR,
        "sqlite3_temp_directory variable should be set for WinRT");
  }
#endif

  /* If the second argument to this function is NULL, generate a 
  ** temporary file name to use 
  */
  if( !zUtf8Name ){
    assert( isDelete && !isOpenJournal );
    rc = winGetTempname(pVfs, &zTmpname);
    if( rc!=SQLITE_OK ){
      OSTRACE(("OPEN name=%s, rc=%s", zUtf8Name, sqlite3ErrName(rc)));
      return rc;
    }
    zUtf8Name = zTmpname;
  }

  /* Database filenames are double-zero terminated if they are not
  ** URIs with parameters.  Hence, they can always be passed into
  ** sqlite3_uri_parameter().
  */
  assert( (eType!=SQLITE_OPEN_MAIN_DB) || (flags & SQLITE_OPEN_URI) ||
       zUtf8Name[sqlite3Strlen30(zUtf8Name)+1]==0 );

  /* Convert the filename to the system encoding. */
  zConverted = winConvertUtf8Filename(zUtf8Name);
  if( zConverted==0 ){
    sqlite3_free(zTmpname);
    OSTRACE(("OPEN name=%s, rc=SQLITE_IOERR_NOMEM", zUtf8Name));
    return SQLITE_IOERR_NOMEM;
  }

  if( winIsDir(zConverted) ){
    sqlite3_free(zConverted);
    sqlite3_free(zTmpname);
    OSTRACE(("OPEN name=%s, rc=SQLITE_CANTOPEN_ISDIR", zUtf8Name));
    return SQLITE_CANTOPEN_ISDIR;
  }

  if( isReadWrite ){
    dwDesiredAccess = GENERIC_READ | GENERIC_WRITE;
  }else{

  }
  /* Reports from the internet are that performance is always
  ** better if FILE_FLAG_RANDOM_ACCESS is used.  Ticket #2699. */
#if SQLITE_OS_WINCE
  dwFlagsAndAttributes |= FILE_FLAG_RANDOM_ACCESS;
#endif

  if( osIsNT() ){
#if SQLITE_OS_WINRT
    CREATEFILE2_EXTENDED_PARAMETERS extendedParameters;
    extendedParameters.dwSize = sizeof(CREATEFILE2_EXTENDED_PARAMETERS);
    extendedParameters.dwFileAttributes =
            dwFlagsAndAttributes & FILE_ATTRIBUTE_MASK;
    extendedParameters.dwFileFlags = dwFlagsAndAttributes & FILE_FLAG_MASK;
    extendedParameters.dwSecurityQosFlags = SECURITY_ANONYMOUS;
    extendedParameters.lpSecurityAttributes = NULL;
    extendedParameters.hTemplateFile = NULL;
    while( (h = osCreateFile2((LPCWSTR)zConverted,
                              dwDesiredAccess,
                              dwShareMode,
                              dwCreationDisposition,
                              &extendedParameters))==INVALID_HANDLE_VALUE &&
                              winRetryIoerr(&cnt, &lastErrno) ){
               /* Noop */
    }
#else
    while( (h = osCreateFileW((LPCWSTR)zConverted,
                              dwDesiredAccess,
                              dwShareMode, NULL,
                              dwCreationDisposition,
                              dwFlagsAndAttributes,
                              NULL))==INVALID_HANDLE_VALUE &&
                              winRetryIoerr(&cnt, &lastErrno) ){
               /* Noop */
    }
#endif
  }
#ifdef SQLITE_WIN32_HAS_ANSI
  else{
    while( (h = osCreateFileA((LPCSTR)zConverted,
                              dwDesiredAccess,
                              dwShareMode, NULL,
                              dwCreationDisposition,
                              dwFlagsAndAttributes,
                              NULL))==INVALID_HANDLE_VALUE &&
                              winRetryIoerr(&cnt, &lastErrno) ){
               /* Noop */
    }
  }
#endif
  winLogIoerr(cnt);

  OSTRACE(("OPEN file=%p, name=%s, access=%lx, rc=%s\n", h, zUtf8Name,
           dwDesiredAccess, (h==INVALID_HANDLE_VALUE) ? "failed" : "ok"));

  if( h==INVALID_HANDLE_VALUE ){
    pFile->lastErrno = lastErrno;
    winLogError(SQLITE_CANTOPEN, pFile->lastErrno, "winOpen", zUtf8Name);
    sqlite3_free(zConverted);
    sqlite3_free(zTmpname);
    if( isReadWrite && !isExclusive ){
      return winOpen(pVfs, zName, id, 
         ((flags|SQLITE_OPEN_READONLY) &
                     ~(SQLITE_OPEN_CREATE|SQLITE_OPEN_READWRITE)),
         pOutFlags);
    }else{
      return SQLITE_CANTOPEN_BKPT;

#if SQLITE_OS_WINCE
  if( isReadWrite && eType==SQLITE_OPEN_MAIN_DB
       && (rc = winceCreateLock(zName, pFile))!=SQLITE_OK
  ){
    osCloseHandle(h);
    sqlite3_free(zConverted);
    sqlite3_free(zTmpname);
    OSTRACE(("OPEN-CE-LOCK name=%s, rc=%s\n", zName, sqlite3ErrName(rc)));
    return rc;
  }
  if( isTemp ){
    pFile->zDeleteOnClose = zConverted;
  }else
#endif
  {
    sqlite3_free(zConverted);
    sqlite3_free(zTmpname);
  }

  pFile->pMethod = &winIoMethod;
  pFile->pVfs = pVfs;
  pFile->h = h;
  if( isReadonly ){
    pFile->ctrlFlags |= WINFILE_RDONLY;

  void *zConverted;
  UNUSED_PARAMETER(pVfs);
  UNUSED_PARAMETER(syncDir);

  SimulateIOError(return SQLITE_IOERR_DELETE);
  OSTRACE(("DELETE name=%s, syncDir=%d\n", zFilename, syncDir));

  zConverted = winConvertUtf8Filename(zFilename);
  if( zConverted==0 ){
    OSTRACE(("DELETE name=%s, rc=SQLITE_IOERR_NOMEM\n", zFilename));
    return SQLITE_IOERR_NOMEM;
  }
  if( osIsNT() ){
    do {
#if SQLITE_OS_WINRT
      WIN32_FILE_ATTRIBUTE_DATA sAttrData;
      memset(&sAttrData, 0, sizeof(sAttrData));
      if ( osGetFileAttributesExW(zConverted, GetFileExInfoStandard,
                                  &sAttrData) ){
        attr = sAttrData.dwFileAttributes;

        rc = SQLITE_ERROR; /* Files only. */
        break;
      }
      if ( osDeleteFileW(zConverted) ){
        rc = SQLITE_OK; /* Deleted OK. */
        break;
      }
      if ( !winRetryIoerr(&cnt, &lastErrno) ){
        rc = SQLITE_ERROR; /* No more retries. */
        break;
      }
    } while(1);
  }
#ifdef SQLITE_WIN32_HAS_ANSI
  else{

        rc = SQLITE_ERROR; /* Files only. */
        break;
      }
      if ( osDeleteFileA(zConverted) ){
        rc = SQLITE_OK; /* Deleted OK. */
        break;
      }
      if ( !winRetryIoerr(&cnt, &lastErrno) ){
        rc = SQLITE_ERROR; /* No more retries. */
        break;
      }
    } while(1);
  }
#endif
  if( rc && rc!=SQLITE_IOERR_DELETE_NOENT ){
    rc = winLogError(SQLITE_IOERR_DELETE, lastErrno,
             "winDelete", zFilename);
  }else{
    winLogIoerr(cnt);
  }
  sqlite3_free(zConverted);
  OSTRACE(("DELETE name=%s, rc=%s\n", zFilename, sqlite3ErrName(rc)));
  return rc;
}

/*

  void *zConverted;
  UNUSED_PARAMETER(pVfs);

  SimulateIOError( return SQLITE_IOERR_ACCESS; );
  OSTRACE(("ACCESS name=%s, flags=%x, pResOut=%p\n",
           zFilename, flags, pResOut));

  zConverted = winConvertUtf8Filename(zFilename);
  if( zConverted==0 ){
    OSTRACE(("ACCESS name=%s, rc=SQLITE_IOERR_NOMEM\n", zFilename));
    return SQLITE_IOERR_NOMEM;
  }
  if( osIsNT() ){
    int cnt = 0;
    WIN32_FILE_ATTRIBUTE_DATA sAttrData;
    memset(&sAttrData, 0, sizeof(sAttrData));
    while( !(rc = osGetFileAttributesExW((LPCWSTR)zConverted,
                             GetFileExInfoStandard, 
                             &sAttrData)) && winRetryIoerr(&cnt, &lastErrno) ){}
    if( rc ){
      /* For an SQLITE_ACCESS_EXISTS query, treat a zero-length file
      ** as if it does not exist.
      */
      if(    flags==SQLITE_ACCESS_EXISTS
          && sAttrData.nFileSizeHigh==0 
          && sAttrData.nFileSizeLow==0 ){
        attr = INVALID_FILE_ATTRIBUTES;
      }else{
        attr = sAttrData.dwFileAttributes;
      }
    }else{
      winLogIoerr(cnt);
      if( lastErrno!=ERROR_FILE_NOT_FOUND && lastErrno!=ERROR_PATH_NOT_FOUND ){
        winLogError(SQLITE_IOERR_ACCESS, lastErrno, "winAccess", zFilename);
        sqlite3_free(zConverted);
        return SQLITE_IOERR_ACCESS;
      }else{
        attr = INVALID_FILE_ATTRIBUTES;
      }

  /*
  ** If the path name starts with a forward slash or a backslash, it is either
  ** a legal UNC name, a volume relative path, or an absolute path name in the
  ** "Unix" format on Windows.  There is no easy way to differentiate between
  ** the final two cases; therefore, we return the safer return value of TRUE
  ** so that callers of this function will simply use it verbatim.
  */
  if ( winIsDirSep(zPathname[0]) ){
    return TRUE;
  }

  /*
  ** If the path name starts with a letter and a colon it is either a volume
  ** relative path or an absolute path.  Callers of this function must not
  ** attempt to treat it as a relative path name (i.e. they should simply use

  int nFull,                    /* Size of output buffer in bytes */
  char *zFull                   /* Output buffer */
){
  
#if defined(__CYGWIN__)
  SimulateIOError( return SQLITE_ERROR );
  UNUSED_PARAMETER(nFull);

  assert( nFull>=pVfs->mxPathname );
  if ( sqlite3_data_directory && !winIsVerbatimPathname(zRelative) ){
    /*
    ** NOTE: We are dealing with a relative path name and the data
    **       directory has been set.  Therefore, use it as the basis
    **       for converting the relative path name to an absolute
    **       one by prepending the data directory and a slash.
    */
    char *zOut = sqlite3MallocZero( pVfs->mxPathname+1 );
    if( !zOut ){
      winLogError(SQLITE_IOERR_NOMEM, 0, "winFullPathname", zRelative);
      return SQLITE_IOERR_NOMEM;
    }
    if( cygwin_conv_path(CCP_POSIX_TO_WIN_A|CCP_RELATIVE, zRelative, zOut,
                         pVfs->mxPathname+1)<0 ){
      winLogError(SQLITE_CANTOPEN_FULLPATH, (DWORD)errno, "cygwin_conv_path",
                  zRelative);
      sqlite3_free(zOut);
      return SQLITE_CANTOPEN_FULLPATH;
    }
    sqlite3_snprintf(MIN(nFull, pVfs->mxPathname), zFull, "%s%s%s",
                     sqlite3_data_directory, winGetDirDep(), zOut);
    sqlite3_free(zOut);
  }else{
    if( cygwin_conv_path(CCP_POSIX_TO_WIN_A, zRelative, zFull, nFull)<0 ){
      winLogError(SQLITE_CANTOPEN_FULLPATH, (DWORD)errno, "cygwin_conv_path",
                  zRelative);
      return SQLITE_CANTOPEN_FULLPATH;
    }
  }

  if ( sqlite3_data_directory && !winIsVerbatimPathname(zRelative) ){
    /*
    ** NOTE: We are dealing with a relative path name and the data
    **       directory has been set.  Therefore, use it as the basis
    **       for converting the relative path name to an absolute
    **       one by prepending the data directory and a backslash.
    */
    sqlite3_snprintf(MIN(nFull, pVfs->mxPathname), zFull, "%s%s%s",
                     sqlite3_data_directory, winGetDirDep(), zRelative);
  }else{
    sqlite3_snprintf(MIN(nFull, pVfs->mxPathname), zFull, "%s", zRelative);
  }
  return SQLITE_OK;
#endif

#if !SQLITE_OS_WINCE && !SQLITE_OS_WINRT && !defined(__CYGWIN__)

  if ( sqlite3_data_directory && !winIsVerbatimPathname(zRelative) ){
    /*
    ** NOTE: We are dealing with a relative path name and the data
    **       directory has been set.  Therefore, use it as the basis
    **       for converting the relative path name to an absolute
    **       one by prepending the data directory and a backslash.
    */
    sqlite3_snprintf(MIN(nFull, pVfs->mxPathname), zFull, "%s%s%s",
                     sqlite3_data_directory, winGetDirDep(), zRelative);
    return SQLITE_OK;
  }
  zConverted = winConvertUtf8Filename(zRelative);
  if( zConverted==0 ){
    return SQLITE_IOERR_NOMEM;
  }
  if( osIsNT() ){
    LPWSTR zTemp;
    nByte = osGetFullPathNameW((LPCWSTR)zConverted, 0, 0, 0);
    if( nByte==0 ){
      winLogError(SQLITE_ERROR, osGetLastError(),
                  "GetFullPathNameW1", zConverted);
      sqlite3_free(zConverted);
      return SQLITE_CANTOPEN_FULLPATH;

      winLogError(SQLITE_ERROR, osGetLastError(),
                  "GetFullPathNameW2", zConverted);
      sqlite3_free(zConverted);
      sqlite3_free(zTemp);
      return SQLITE_CANTOPEN_FULLPATH;
    }
    sqlite3_free(zConverted);
    zOut = winUnicodeToUtf8(zTemp);
    sqlite3_free(zTemp);
  }
#ifdef SQLITE_WIN32_HAS_ANSI
  else{
    char *zTemp;
    nByte = osGetFullPathNameA((char*)zConverted, 0, 0, 0);
    if( nByte==0 ){

*/
/*
** Interfaces for opening a shared library, finding entry points
** within the shared library, and closing the shared library.
*/
static void *winDlOpen(sqlite3_vfs *pVfs, const char *zFilename){
  HANDLE h;
  void *zConverted = winConvertUtf8Filename(zFilename);
  UNUSED_PARAMETER(pVfs);
  if( zConverted==0 ){
    return 0;
  }
  if( osIsNT() ){
#if SQLITE_OS_WINRT
    h = osLoadPackagedLibrary((LPCWSTR)zConverted, 0);
#else
    h = osLoadLibraryW((LPCWSTR)zConverted);
#endif
  }
#ifdef SQLITE_WIN32_HAS_ANSI
  else{
    h = osLoadLibraryA((char*)zConverted);
  }
#endif
  sqlite3_free(zConverted);
  return (void*)h;
}
static void winDlError(sqlite3_vfs *pVfs, int nBuf, char *zBufOut){
  UNUSED_PARAMETER(pVfs);
  winGetLastErrorMsg(osGetLastError(), nBuf, zBufOut);
}
static void (*winDlSym(sqlite3_vfs *pVfs,void *pH,const char *zSym))(void){
  UNUSED_PARAMETER(pVfs);
  return (void(*)(void))osGetProcAddressA((HANDLE)pH, zSym);
}
static void winDlClose(sqlite3_vfs *pVfs, void *pHandle){
  UNUSED_PARAMETER(pVfs);

**
** However if an error message is supplied, it will be incorporated
** by sqlite into the error message available to the user using
** sqlite3_errmsg(), possibly making IO errors easier to debug.
*/
static int winGetLastError(sqlite3_vfs *pVfs, int nBuf, char *zBuf){
  UNUSED_PARAMETER(pVfs);
  return winGetLastErrorMsg(osGetLastError(), nBuf, zBuf);
}

/*
** Initialize and deinitialize the operating system interface.
*/
SQLITE_API int sqlite3_os_init(void){
  static sqlite3_vfs winVfs = {
    3,                   /* iVersion */
    sizeof(winFile),     /* szOsFile */
    SQLITE_WIN32_MAX_PATH_BYTES, /* mxPathname */
    0,                   /* pNext */
    "win32",             /* zName */
    0,                   /* pAppData */
    winOpen,             /* xOpen */
    winDelete,           /* xDelete */
    winAccess,           /* xAccess */
    winFullPathname,     /* xFullPathname */
    winDlOpen,           /* xDlOpen */
    winDlError,          /* xDlError */
    winDlSym,            /* xDlSym */
    winDlClose,          /* xDlClose */
    winRandomness,       /* xRandomness */
    winSleep,            /* xSleep */
    winCurrentTime,      /* xCurrentTime */
    winGetLastError,     /* xGetLastError */
    winCurrentTimeInt64, /* xCurrentTimeInt64 */
    winSetSystemCall,    /* xSetSystemCall */
    winGetSystemCall,    /* xGetSystemCall */
    winNextSystemCall,   /* xNextSystemCall */
  };
#if defined(SQLITE_WIN32_HAS_WIDE)
  static sqlite3_vfs winLongPathVfs = {
    3,                   /* iVersion */
    sizeof(winFile),     /* szOsFile */
    SQLITE_WINNT_MAX_PATH_BYTES, /* mxPathname */
    0,                   /* pNext */
    "win32-longpath",    /* zName */
    0,                   /* pAppData */
    winOpen,             /* xOpen */
    winDelete,           /* xDelete */
    winAccess,           /* xAccess */
    winFullPathname,     /* xFullPathname */
    winDlOpen,           /* xDlOpen */
    winDlError,          /* xDlError */
    winDlSym,            /* xDlSym */
    winDlClose,          /* xDlClose */
    winRandomness,       /* xRandomness */
    winSleep,            /* xSleep */
    winCurrentTime,      /* xCurrentTime */
    winGetLastError,     /* xGetLastError */
    winCurrentTimeInt64, /* xCurrentTimeInt64 */
    winSetSystemCall,    /* xSetSystemCall */
    winGetSystemCall,    /* xGetSystemCall */
    winNextSystemCall,   /* xNextSystemCall */
  };
#endif

  /* Double-check that the aSyscall[] array has been constructed
  ** correctly.  See ticket [bb3a86e890c8e96ab] */
  assert( ArraySize(aSyscall)==74 );

  /* get memory map allocation granularity */
  memset(&winSysInfo, 0, sizeof(SYSTEM_INFO));
#if SQLITE_OS_WINRT
  osGetNativeSystemInfo(&winSysInfo);
#else
  osGetSystemInfo(&winSysInfo);
#endif
  assert( winSysInfo.dwAllocationGranularity>0 );
  assert( winSysInfo.dwPageSize>0 );

  sqlite3_vfs_register(&winVfs, 1);

#if defined(SQLITE_WIN32_HAS_WIDE)
  sqlite3_vfs_register(&winLongPathVfs, 0);
#endif

  return SQLITE_OK; 
}

SQLITE_API int sqlite3_os_end(void){ 
#if SQLITE_OS_WINRT
  if( sleepObj!=NULL ){
    osCloseHandle(sleepObj);

    pBt->max1bytePayload = 127;
  }else{
    pBt->max1bytePayload = (u8)pBt->maxLocal;
  }
  assert( pBt->maxLeaf + 23 <= MX_CELL_SIZE(pBt) );
  pBt->pPage1 = pPage1;
  pBt->nPage = nPage;
assert( pPage1->leaf==0 || pPage1->leaf==1 );
  return SQLITE_OK;

page1_init_failed:
  releasePage(pPage1);
  pBt->pPage1 = 0;
  return rc;
}

    p->type = SQLITE_NULL;
    p->db = db;
  }
  return p;
}

/*
** Context object passed by sqlite3Stat4ProbeSetValue() through to 
** valueNew(). See comments above valueNew() for details.
*/
struct ValueNewStat4Ctx {
  Parse *pParse;
  Index *pIdx;
  UnpackedRecord **ppRec;
  int iVal;
};

/*
** Allocate and return a pointer to a new sqlite3_value object. If
** the second argument to this function is NULL, the object is allocated
** by calling sqlite3ValueNew().
**
** Otherwise, if the second argument is non-zero, then this function is 
** being called indirectly by sqlite3Stat4ProbeSetValue(). If it has not
** already been allocated, allocate the UnpackedRecord structure that 
** that function will return to its caller here. Then return a pointer 
** an sqlite3_value within the UnpackedRecord.a[] array.
*/
static sqlite3_value *valueNew(sqlite3 *db, struct ValueNewStat4Ctx *p){
#ifdef SQLITE_ENABLE_STAT3_OR_STAT4
  if( p ){
    UnpackedRecord *pRec = p->ppRec[0];

    if( pRec==0 ){
      Index *pIdx = p->pIdx;      /* Index being probed */
      int nByte;                  /* Bytes of space to allocate */
      int i;                      /* Counter variable */
      int nCol = pIdx->nColumn+1; /* Number of index columns including rowid */
  
      nByte = sizeof(Mem) * nCol + sizeof(UnpackedRecord);
      pRec = (UnpackedRecord*)sqlite3DbMallocZero(db, nByte);
      if( pRec ){
        pRec->pKeyInfo = sqlite3IndexKeyinfo(p->pParse, pIdx);
        if( pRec->pKeyInfo ){
          assert( pRec->pKeyInfo->nField+1==nCol );
          pRec->pKeyInfo->enc = ENC(db);
          pRec->flags = UNPACKED_PREFIX_MATCH;
          pRec->aMem = (Mem *)&pRec[1];
          for(i=0; i<nCol; i++){
            pRec->aMem[i].flags = MEM_Null;
            pRec->aMem[i].type = SQLITE_NULL;
            pRec->aMem[i].db = db;
          }
        }else{
          sqlite3DbFree(db, pRec);
          pRec = 0;
        }
      }
      if( pRec==0 ) return 0;
      p->ppRec[0] = pRec;
    }
  
    pRec->nField = p->iVal+1;
    return &pRec->aMem[p->iVal];
  }
#endif
  return sqlite3ValueNew(db);
}

/*
** Extract a value from the supplied expression in the manner described
** above sqlite3ValueFromExpr(). Allocate the sqlite3_value object
** using valueNew().
**
** If pCtx is NULL and an error occurs after the sqlite3_value object
** has been allocated, it is freed before returning. Or, if pCtx is not
** NULL, it is assumed that the caller will free any allocated object
** in all cases.
*/
int valueFromExpr(
  sqlite3 *db,                    /* The database connection */
  Expr *pExpr,                    /* The expression to evaluate */
  u8 enc,                         /* Encoding to use */
  u8 affinity,                    /* Affinity to use */
  sqlite3_value **ppVal,          /* Write the new value here */
  struct ValueNewStat4Ctx *pCtx   /* Second argument for valueNew() */
){
  int op;
  char *zVal = 0;
  sqlite3_value *pVal = 0;
  int negInt = 1;
  const char *zNeg = "";
  int rc = SQLITE_OK;

  if( !pExpr ){
    *ppVal = 0;
    return SQLITE_OK;
  }
  op = pExpr->op;

  /* op can only be TK_REGISTER if we have compiled with SQLITE_ENABLE_STAT4.
  ** The ifdef here is to enable us to achieve 100% branch test coverage even
  ** when SQLITE_ENABLE_STAT4 is omitted.
  */
#ifdef SQLITE_ENABLE_STAT3_OR_STAT4
  if( op==TK_REGISTER ) op = pExpr->op2;
#else
  if( NEVER(op==TK_REGISTER) ) op = pExpr->op2;
#endif

  /* Handle negative integers in a single step.  This is needed in the
  ** case when the value is -9223372036854775808.
  */
  if( op==TK_UMINUS
   && (pExpr->pLeft->op==TK_INTEGER || pExpr->pLeft->op==TK_FLOAT) ){
    pExpr = pExpr->pLeft;
    op = pExpr->op;
    negInt = -1;
    zNeg = "-";
  }

  if( op==TK_STRING || op==TK_FLOAT || op==TK_INTEGER ){
    pVal = valueNew(db, pCtx);
    if( pVal==0 ) goto no_mem;
    if( ExprHasProperty(pExpr, EP_IntValue) ){
      sqlite3VdbeMemSetInt64(pVal, (i64)pExpr->u.iValue*negInt);
    }else{
      zVal = sqlite3MPrintf(db, "%s%s", zNeg, pExpr->u.zToken);
      if( zVal==0 ) goto no_mem;
      sqlite3ValueSetStr(pVal, -1, zVal, SQLITE_UTF8, SQLITE_DYNAMIC);
      if( op==TK_FLOAT ) pVal->type = SQLITE_FLOAT;
    }
    if( (op==TK_INTEGER || op==TK_FLOAT ) && affinity==SQLITE_AFF_NONE ){
      sqlite3ValueApplyAffinity(pVal, SQLITE_AFF_NUMERIC, SQLITE_UTF8);
    }else{
      sqlite3ValueApplyAffinity(pVal, affinity, SQLITE_UTF8);
    }
    if( pVal->flags & (MEM_Int|MEM_Real) ) pVal->flags &= ~MEM_Str;
    if( enc!=SQLITE_UTF8 ){
      rc = sqlite3VdbeChangeEncoding(pVal, enc);
    }
  }else if( op==TK_UMINUS ) {
    /* This branch happens for multiple negative signs.  Ex: -(-5) */
    if( SQLITE_OK==sqlite3ValueFromExpr(db,pExpr->pLeft,enc,affinity,&pVal) 
     && pVal!=0
    ){
      sqlite3VdbeMemNumerify(pVal);
      if( pVal->u.i==SMALLEST_INT64 ){
        pVal->flags &= MEM_Int;
        pVal->flags |= MEM_Real;
        pVal->r = (double)LARGEST_INT64;
      }else{
        pVal->u.i = -pVal->u.i;
      }
      pVal->r = -pVal->r;
      sqlite3ValueApplyAffinity(pVal, affinity, enc);
    }
  }else if( op==TK_NULL ){
    pVal = valueNew(db, pCtx);
    if( pVal==0 ) goto no_mem;
  }
#ifndef SQLITE_OMIT_BLOB_LITERAL
  else if( op==TK_BLOB ){
    int nVal;
    assert( pExpr->u.zToken[0]=='x' || pExpr->u.zToken[0]=='X' );
    assert( pExpr->u.zToken[1]=='\'' );
    pVal = valueNew(db, pCtx);
    if( !pVal ) goto no_mem;
    zVal = &pExpr->u.zToken[2];
    nVal = sqlite3Strlen30(zVal)-1;
    assert( zVal[nVal]=='\'' );
    sqlite3VdbeMemSetStr(pVal, sqlite3HexToBlob(db, zVal, nVal), nVal/2,
                         0, SQLITE_DYNAMIC);
  }
#endif

  if( pVal ){
    sqlite3VdbeMemStoreType(pVal);
  }
  *ppVal = pVal;
  return rc;

no_mem:
  db->mallocFailed = 1;
  sqlite3DbFree(db, zVal);
  assert( *ppVal==0 );
#ifdef SQLITE_ENABLE_STAT3_OR_STAT4
  if( pCtx==0 ) sqlite3ValueFree(pVal);
#else
  assert( pCtx==0 ); sqlite3ValueFree(pVal);
#endif
  return SQLITE_NOMEM;
}

/*
** Create a new sqlite3_value object, containing the value of pExpr.
**
** This only works for very simple expressions that consist of one constant
** token (i.e. "5", "5.1", "'a string'"). If the expression can
** be converted directly into a value, then the value is allocated and
** a pointer written to *ppVal. The caller is responsible for deallocating
** the value by passing it to sqlite3ValueFree() later on. If the expression
** cannot be converted to a value, then *ppVal is set to NULL.
*/
SQLITE_PRIVATE int sqlite3ValueFromExpr(
  sqlite3 *db,              /* The database connection */
  Expr *pExpr,              /* The expression to evaluate */
  u8 enc,                   /* Encoding to use */
  u8 affinity,              /* Affinity to use */
  sqlite3_value **ppVal     /* Write the new value here */
){
  return valueFromExpr(db, pExpr, enc, affinity, ppVal, 0);
}

#ifdef SQLITE_ENABLE_STAT3_OR_STAT4
/*
** The implementation of the sqlite_record() function. This function accepts
** a single argument of any type. The return value is a formatted database 
** record (a blob) containing the argument value.
**
** This is used to convert the value stored in the 'sample' column of the
** sqlite_stat3 table to the record format SQLite uses internally.
*/
static void recordFunc(
  sqlite3_context *context,
  int argc,
  sqlite3_value **argv
){
  const int file_format = 1;
  int iSerial;                    /* Serial type */
  int nSerial;                    /* Bytes of space for iSerial as varint */
  int nVal;                       /* Bytes of space required for argv[0] */
  int nRet;
  sqlite3 *db;
  u8 *aRet;

  iSerial = sqlite3VdbeSerialType(argv[0], file_format);
  nSerial = sqlite3VarintLen(iSerial);
  nVal = sqlite3VdbeSerialTypeLen(iSerial);
  db = sqlite3_context_db_handle(context);

  nRet = 1 + nSerial + nVal;
  aRet = sqlite3DbMallocRaw(db, nRet);
  if( aRet==0 ){
    sqlite3_result_error_nomem(context);
  }else{
    aRet[0] = nSerial+1;
    sqlite3PutVarint(&aRet[1], iSerial);
    sqlite3VdbeSerialPut(&aRet[1+nSerial], nVal, argv[0], file_format);
    sqlite3_result_blob(context, aRet, nRet, SQLITE_TRANSIENT);
    sqlite3DbFree(db, aRet);
  }
}

/*
** Register built-in functions used to help read ANALYZE data.
*/
SQLITE_PRIVATE void sqlite3AnalyzeFunctions(void){
  static SQLITE_WSD FuncDef aAnalyzeTableFuncs[] = {
    FUNCTION(sqlite_record,   1, 0, 0, recordFunc),
  };
  int i;
  FuncDefHash *pHash = &GLOBAL(FuncDefHash, sqlite3GlobalFunctions);
  FuncDef *aFunc = (FuncDef*)&GLOBAL(FuncDef, aAnalyzeTableFuncs);
  for(i=0; i<ArraySize(aAnalyzeTableFuncs); i++){
    sqlite3FuncDefInsert(pHash, &aFunc[i]);
  }
}

/*
** This function is used to allocate and populate UnpackedRecord 
** structures intended to be compared against sample index keys stored 
** in the sqlite_stat4 table.
**
** A single call to this function attempts to populates field iVal (leftmost 
** is 0 etc.) of the unpacked record with a value extracted from expression
** pExpr. Extraction of values is possible if:
**
**  * (pExpr==0). In this case the value is assumed to be an SQL NULL,
**
**  * The expression is a bound variable, and this is a reprepare, or
**
**  * The sqlite3ValueFromExpr() function is able to extract a value 
**    from the expression (i.e. the expression is a literal value).
**
** If a value can be extracted, the affinity passed as the 5th argument
** is applied to it before it is copied into the UnpackedRecord. Output
** parameter *pbOk is set to true if a value is extracted, or false 
** otherwise.
**
** When this function is called, *ppRec must either point to an object
** allocated by an earlier call to this function, or must be NULL. If it
** is NULL and a value can be successfully extracted, a new UnpackedRecord
** is allocated (and *ppRec set to point to it) before returning.
**
** Unless an error is encountered, SQLITE_OK is returned. It is not an
** error if a value cannot be extracted from pExpr. If an error does
** occur, an SQLite error code is returned.
*/
SQLITE_PRIVATE int sqlite3Stat4ProbeSetValue(
  Parse *pParse,                  /* Parse context */
  Index *pIdx,                    /* Index being probed */
  UnpackedRecord **ppRec,         /* IN/OUT: Probe record */
  Expr *pExpr,                    /* The expression to extract a value from */
  u8 affinity,                    /* Affinity to use */
  int iVal,                       /* Array element to populate */
  int *pbOk                       /* OUT: True if value was extracted */
){
  int rc = SQLITE_OK;
  sqlite3_value *pVal = 0;

  struct ValueNewStat4Ctx alloc;
  alloc.pParse = pParse;
  alloc.pIdx = pIdx;
  alloc.ppRec = ppRec;
  alloc.iVal = iVal;

  if( !pExpr ){
    pVal = valueNew(pParse->db, &alloc);
    if( pVal ){
      sqlite3VdbeMemSetNull((Mem*)pVal);
      *pbOk = 1;
    }
  }else if( pExpr->op==TK_VARIABLE
        || (pExpr->op==TK_REGISTER && pExpr->op2==TK_VARIABLE)
  ){
    Vdbe *v;
    int iBindVar = pExpr->iColumn;
    sqlite3VdbeSetVarmask(pParse->pVdbe, iBindVar);
    if( (v = pParse->pReprepare)!=0 ){
      pVal = valueNew(pParse->db, &alloc);
      if( pVal ){
        rc = sqlite3VdbeMemCopy((Mem*)pVal, &v->aVar[iBindVar-1]);
        if( rc==SQLITE_OK ){
          sqlite3ValueApplyAffinity(pVal, affinity, SQLITE_UTF8);
        }
        pVal->db = pParse->db;
        *pbOk = 1;
        sqlite3VdbeMemStoreType((Mem*)pVal);
      }
    }else{
      *pbOk = 0;
    }
  }else{
    sqlite3 *db = pParse->db;
    rc = valueFromExpr(db, pExpr, ENC(db), affinity, &pVal, &alloc);
    *pbOk = (pVal!=0);
  }

  assert( pVal==0 || pVal->db==pParse->db );
  return rc;
}

/*
** Unless it is NULL, the argument must be an UnpackedRecord object returned
** by an earlier call to sqlite3Stat4ProbeSetValue(). This call deletes
** the object.
*/
SQLITE_PRIVATE void sqlite3Stat4ProbeFree(UnpackedRecord *pRec){
  if( pRec ){
    int i;
    int nCol = pRec->pKeyInfo->nField+1;
    Mem *aMem = pRec->aMem;
    sqlite3 *db = aMem[0].db;
    for(i=0; i<nCol; i++){
      sqlite3DbFree(db, aMem[i].zMalloc);
    }
    sqlite3DbFree(db, pRec->pKeyInfo);
    sqlite3DbFree(db, pRec);
  }
}
#endif /* ifdef SQLITE_ENABLE_STAT4 */

/*
** Change the string value of an sqlite3_value object
*/
SQLITE_PRIVATE void sqlite3ValueSetStr(
  sqlite3_value *v,     /* Value to be set */
  int n,                /* Length of string z */
  const void *z,        /* Text of the new string */

    ** external allocations out of mem[p2] and set mem[p2] to be
    ** an undefined integer.  Opcodes will either fill in the integer
    ** value or convert mem[p2] to a different type.
    */
    assert( pOp->opflags==sqlite3OpcodeProperty[pOp->opcode] );
    if( pOp->opflags & OPFLG_OUT2_PRERELEASE ){
      assert( pOp->p2>0 );
      assert( pOp->p2<=(p->nMem-p->nCursor) );
      pOut = &aMem[pOp->p2];
      memAboutToChange(p, pOut);
      VdbeMemRelease(pOut);
      pOut->flags = MEM_Int;
    }

    /* Sanity checking on other operands */
#ifdef SQLITE_DEBUG
    if( (pOp->opflags & OPFLG_IN1)!=0 ){
      assert( pOp->p1>0 );
      assert( pOp->p1<=(p->nMem-p->nCursor) );
      assert( memIsValid(&aMem[pOp->p1]) );
      REGISTER_TRACE(pOp->p1, &aMem[pOp->p1]);
    }
    if( (pOp->opflags & OPFLG_IN2)!=0 ){
      assert( pOp->p2>0 );
      assert( pOp->p2<=(p->nMem-p->nCursor) );
      assert( memIsValid(&aMem[pOp->p2]) );
      REGISTER_TRACE(pOp->p2, &aMem[pOp->p2]);
    }
    if( (pOp->opflags & OPFLG_IN3)!=0 ){
      assert( pOp->p3>0 );
      assert( pOp->p3<=(p->nMem-p->nCursor) );
      assert( memIsValid(&aMem[pOp->p3]) );
      REGISTER_TRACE(pOp->p3, &aMem[pOp->p3]);
    }
    if( (pOp->opflags & OPFLG_OUT2)!=0 ){
      assert( pOp->p2>0 );
      assert( pOp->p2<=(p->nMem-p->nCursor) );
      memAboutToChange(p, &aMem[pOp->p2]);
    }
    if( (pOp->opflags & OPFLG_OUT3)!=0 ){
      assert( pOp->p3>0 );
      assert( pOp->p3<=(p->nMem-p->nCursor) );
      memAboutToChange(p, &aMem[pOp->p3]);
    }
#endif
  
    switch( pOp->opcode ){

/*****************************************************************************

/* Opcode:  Gosub P1 P2 * * *
**
** Write the current address onto register P1
** and then jump to address P2.
*/
case OP_Gosub: {            /* jump */
  assert( pOp->p1>0 && pOp->p1<=(p->nMem-p->nCursor) );
  pIn1 = &aMem[pOp->p1];
  assert( (pIn1->flags & MEM_Dyn)==0 );
  memAboutToChange(p, pIn1);
  pIn1->flags = MEM_Int;
  pIn1->u.i = pc;
  REGISTER_TRACE(pOp->p1, pIn1);
  pc = pOp->p2 - 1;

*/
case OP_Null: {           /* out2-prerelease */
#if 0  /* local variables moved into u.ab */
  int cnt;
  u16 nullFlag;
#endif /* local variables moved into u.ab */
  u.ab.cnt = pOp->p3-pOp->p2;
  assert( pOp->p3<=(p->nMem-p->nCursor) );
  pOut->flags = u.ab.nullFlag = pOp->p1 ? (MEM_Null|MEM_Cleared) : MEM_Null;
  while( u.ab.cnt>0 ){
    pOut++;
    memAboutToChange(p, pOut);
    VdbeMemRelease(pOut);
    pOut->flags = u.ab.nullFlag;
    u.ab.cnt--;

  u.ad.p2 = pOp->p2;
  assert( u.ad.n>0 && u.ad.p1>0 && u.ad.p2>0 );
  assert( u.ad.p1+u.ad.n<=u.ad.p2 || u.ad.p2+u.ad.n<=u.ad.p1 );

  pIn1 = &aMem[u.ad.p1];
  pOut = &aMem[u.ad.p2];
  while( u.ad.n-- ){
    assert( pOut<=&aMem[(p->nMem-p->nCursor)] );
    assert( pIn1<=&aMem[(p->nMem-p->nCursor)] );
    assert( memIsValid(pIn1) );
    memAboutToChange(p, pOut);
    u.ad.zMalloc = pOut->zMalloc;
    pOut->zMalloc = 0;
    sqlite3VdbeMemMove(pOut, pIn1);
#ifdef SQLITE_DEBUG
    if( pOut->pScopyFrom>=&aMem[u.ad.p1] && pOut->pScopyFrom<&aMem[u.ad.p1+pOp->p3] ){

case OP_ResultRow: {
#if 0  /* local variables moved into u.af */
  Mem *pMem;
  int i;
#endif /* local variables moved into u.af */
  assert( p->nResColumn==pOp->p2 );
  assert( pOp->p1>0 );
  assert( pOp->p1+pOp->p2<=(p->nMem-p->nCursor)+1 );

  /* If this statement has violated immediate foreign key constraints, do
  ** not return the number of rows modified. And do not RELEASE the statement
  ** transaction. It needs to be rolled back.  */
  if( SQLITE_OK!=(rc = sqlite3VdbeCheckFk(p, 0)) ){
    assert( db->flags&SQLITE_CountRows );
    assert( p->usesStmtJournal );

  sqlite3_value **apVal;
  int n;
#endif /* local variables moved into u.ai */

  u.ai.n = pOp->p5;
  u.ai.apVal = p->apArg;
  assert( u.ai.apVal || u.ai.n==0 );
  assert( pOp->p3>0 && pOp->p3<=(p->nMem-p->nCursor) );
  pOut = &aMem[pOp->p3];
  memAboutToChange(p, pOut);

  assert( u.ai.n==0 || (pOp->p2>0 && pOp->p2+u.ai.n<=(p->nMem-p->nCursor)+1) );
  assert( pOp->p3<pOp->p2 || pOp->p3>=pOp->p2+u.ai.n );
  u.ai.pArg = &aMem[pOp->p2];
  for(u.ai.i=0; u.ai.i<u.ai.n; u.ai.i++, u.ai.pArg++){
    assert( memIsValid(u.ai.pArg) );
    u.ai.apVal[u.ai.i] = u.ai.pArg;
    Deephemeralize(u.ai.pArg);
    sqlite3VdbeMemStoreType(u.ai.pArg);

  assert( u.al.pKeyInfo!=0 );
  u.al.p1 = pOp->p1;
  u.al.p2 = pOp->p2;
#if SQLITE_DEBUG
  if( aPermute ){
    int k, mx = 0;
    for(k=0; k<u.al.n; k++) if( aPermute[k]>mx ) mx = aPermute[k];
    assert( u.al.p1>0 && u.al.p1+mx<=(p->nMem-p->nCursor)+1 );
    assert( u.al.p2>0 && u.al.p2+mx<=(p->nMem-p->nCursor)+1 );
  }else{
    assert( u.al.p1>0 && u.al.p1+u.al.n<=(p->nMem-p->nCursor)+1 );
    assert( u.al.p2>0 && u.al.p2+u.al.n<=(p->nMem-p->nCursor)+1 );
  }
#endif /* SQLITE_DEBUG */
  for(u.al.i=0; u.al.i<u.al.n; u.al.i++){
    u.al.idx = aPermute ? aPermute[u.al.i] : u.al.i;
    assert( memIsValid(&aMem[u.al.p1+u.al.idx]) );
    assert( memIsValid(&aMem[u.al.p2+u.al.idx]) );
    REGISTER_TRACE(u.al.p1+u.al.idx, &aMem[u.al.p1+u.al.idx]);

  u.ao.p1 = pOp->p1;
  u.ao.p2 = pOp->p2;
  u.ao.pC = 0;
  memset(&u.ao.sMem, 0, sizeof(u.ao.sMem));
  assert( u.ao.p1<p->nCursor );
  assert( pOp->p3>0 && pOp->p3<=(p->nMem-p->nCursor) );
  u.ao.pDest = &aMem[pOp->p3];
  memAboutToChange(p, u.ao.pDest);
  u.ao.zRec = 0;

  /* This block sets the variable u.ao.payloadSize to be the total number of
  ** bytes in the record.
  **

#endif /* local variables moved into u.ap */

  u.ap.zAffinity = pOp->p4.z;
  assert( u.ap.zAffinity!=0 );
  assert( u.ap.zAffinity[pOp->p2]==0 );
  pIn1 = &aMem[pOp->p1];
  while( (u.ap.cAff = *(u.ap.zAffinity++))!=0 ){
    assert( pIn1 <= &p->aMem[(p->nMem-p->nCursor)] );
    assert( memIsValid(pIn1) );
    ExpandBlob(pIn1);
    applyAffinity(pIn1, u.ap.cAff, encoding);
    pIn1++;
  }
  break;
}

  ** of the record to data0.
  */
  u.aq.nData = 0;         /* Number of bytes of data space */
  u.aq.nHdr = 0;          /* Number of bytes of header space */
  u.aq.nZero = 0;         /* Number of zero bytes at the end of the record */
  u.aq.nField = pOp->p1;
  u.aq.zAffinity = pOp->p4.z;
  assert( u.aq.nField>0 && pOp->p2>0 && pOp->p2+u.aq.nField<=(p->nMem-p->nCursor)+1 );
  u.aq.pData0 = &aMem[u.aq.nField];
  u.aq.nField = pOp->p2;
  u.aq.pLast = &u.aq.pData0[u.aq.nField-1];
  u.aq.file_format = p->minWriteFileFormat;

  /* Identify the output register */
  assert( pOp->p3<pOp->p1 || pOp->p3>=pOp->p1+pOp->p2 );

    u.aq.i += putVarint32(&u.aq.zNewRecord[u.aq.i], u.aq.serial_type);      /* serial type */
  }
  for(u.aq.pRec=u.aq.pData0; u.aq.pRec<=u.aq.pLast; u.aq.pRec++){  /* serial data */
    u.aq.i += sqlite3VdbeSerialPut(&u.aq.zNewRecord[u.aq.i], (int)(u.aq.nByte-u.aq.i), u.aq.pRec,u.aq.file_format);
  }
  assert( u.aq.i==u.aq.nByte );

  assert( pOp->p3>0 && pOp->p3<=(p->nMem-p->nCursor) );
  pOut->n = (int)u.aq.nByte;
  pOut->flags = MEM_Blob | MEM_Dyn;
  pOut->xDel = 0;
  if( u.aq.nZero ){
    pOut->u.nZero = u.aq.nZero;
    pOut->flags |= MEM_Zero;
  }

      p->minWriteFileFormat = u.ay.pDb->pSchema->file_format;
    }
  }else{
    u.ay.wrFlag = 0;
  }
  if( pOp->p5 & OPFLAG_P2ISREG ){
    assert( u.ay.p2>0 );
    assert( u.ay.p2<=(p->nMem-p->nCursor) );
    pIn2 = &aMem[u.ay.p2];
    assert( memIsValid(pIn2) );
    assert( (pIn2->flags & MEM_Int)!=0 );
    sqlite3VdbeMemIntegerify(pIn2);
    u.ay.p2 = (int)pIn2->u.i;
    /* The u.ay.p2 value always comes from a prior OP_CreateTable opcode and
    ** that opcode will always set the u.ay.p2 value to 2 or more or else fail.

  i64 R;                             /* Rowid stored in register P3 */
#endif /* local variables moved into u.bf */

  pIn3 = &aMem[pOp->p3];
  u.bf.aMx = &aMem[pOp->p4.i];
  /* Assert that the values of parameters P1 and P4 are in range. */
  assert( pOp->p4type==P4_INT32 );
  assert( pOp->p4.i>0 && pOp->p4.i<=(p->nMem-p->nCursor) );
  assert( pOp->p1>=0 && pOp->p1<p->nCursor );

  /* Find the index cursor. */
  u.bf.pCx = p->apCsr[pOp->p1];
  assert( u.bf.pCx->deferredMoveto==0 );
  u.bf.pCx->seekResult = 0;
  u.bf.pCx->cacheStatus = CACHE_STALE;

        if( p->pFrame ){
          for(u.bh.pFrame=p->pFrame; u.bh.pFrame->pParent; u.bh.pFrame=u.bh.pFrame->pParent);
          /* Assert that P3 is a valid memory cell. */
          assert( pOp->p3<=u.bh.pFrame->nMem );
          u.bh.pMem = &u.bh.pFrame->aMem[pOp->p3];
        }else{
          /* Assert that P3 is a valid memory cell. */
          assert( pOp->p3<=(p->nMem-p->nCursor) );
          u.bh.pMem = &aMem[pOp->p3];
          memAboutToChange(p, u.bh.pMem);
        }
        assert( memIsValid(u.bh.pMem) );

        REGISTER_TRACE(pOp->p3, u.bh.pMem);
        sqlite3VdbeMemIntegerify(u.bh.pMem);

  VdbeCursor *pC;
  BtCursor *pCrsr;
  int res;
  UnpackedRecord r;
#endif /* local variables moved into u.bt */

  assert( pOp->p3>0 );
  assert( pOp->p2>0 && pOp->p2+pOp->p3<=(p->nMem-p->nCursor)+1 );
  assert( pOp->p1>=0 && pOp->p1<p->nCursor );
  u.bt.pC = p->apCsr[pOp->p1];
  assert( u.bt.pC!=0 );
  u.bt.pCrsr = u.bt.pC->pCursor;
  if( ALWAYS(u.bt.pCrsr!=0) ){
    u.bt.r.pKeyInfo = u.bt.pC->pKeyInfo;
    u.bt.r.nField = (u16)pOp->p3;

case OP_Clear: {
#if 0  /* local variables moved into u.bx */
  int nChange;
#endif /* local variables moved into u.bx */

  u.bx.nChange = 0;
  assert( p->readOnly==0 );
  assert( pOp->p1!=1 );
  assert( (p->btreeMask & (((yDbMask)1)<<pOp->p2))!=0 );
  rc = sqlite3BtreeClearTable(
      db->aDb[pOp->p2].pBt, pOp->p1, (pOp->p3 ? &u.bx.nChange : 0)
  );
  if( pOp->p3 ){
    p->nChange += u.bx.nChange;
    if( pOp->p3>0 ){

#endif /* local variables moved into u.ca */

  assert( p->bIsReader );
  u.ca.nRoot = pOp->p2;
  assert( u.ca.nRoot>0 );
  u.ca.aRoot = sqlite3DbMallocRaw(db, sizeof(int)*(u.ca.nRoot+1) );
  if( u.ca.aRoot==0 ) goto no_mem;
  assert( pOp->p3>0 && pOp->p3<=(p->nMem-p->nCursor) );
  u.ca.pnErr = &aMem[pOp->p3];
  assert( (u.ca.pnErr->flags & MEM_Int)!=0 );
  assert( (u.ca.pnErr->flags & (MEM_Str|MEM_Blob))==0 );
  pIn1 = &aMem[pOp->p1];
  for(u.ca.j=0; u.ca.j<u.ca.nRoot; u.ca.j++){
    u.ca.aRoot[u.ca.j] = (int)sqlite3VdbeIntValue(&pIn1[u.ca.j]);
  }

  for(u.cg.i=0; u.cg.i<u.cg.n; u.cg.i++, u.cg.pRec++){
    assert( memIsValid(u.cg.pRec) );
    u.cg.apVal[u.cg.i] = u.cg.pRec;
    memAboutToChange(p, u.cg.pRec);
    sqlite3VdbeMemStoreType(u.cg.pRec);
  }
  u.cg.ctx.pFunc = pOp->p4.pFunc;
  assert( pOp->p3>0 && pOp->p3<=(p->nMem-p->nCursor) );
  u.cg.ctx.pMem = u.cg.pMem = &aMem[pOp->p3];
  u.cg.pMem->n++;
  u.cg.ctx.s.flags = MEM_Null;
  u.cg.ctx.s.z = 0;
  u.cg.ctx.s.zMalloc = 0;
  u.cg.ctx.s.xDel = 0;
  u.cg.ctx.s.db = db;

** P4 argument is only needed for the degenerate case where
** the step function was not previously called.
*/
case OP_AggFinal: {
#if 0  /* local variables moved into u.ch */
  Mem *pMem;
#endif /* local variables moved into u.ch */
  assert( pOp->p1>0 && pOp->p1<=(p->nMem-p->nCursor) );
  u.ch.pMem = &aMem[pOp->p1];
  assert( (u.ch.pMem->flags & ~(MEM_Null|MEM_Agg))==0 );
  rc = sqlite3VdbeMemFinalize(u.ch.pMem, pOp->p4.pFunc);
  if( rc ){
    sqlite3SetString(&p->zErrMsg, db, "%s", sqlite3_value_text(u.ch.pMem));
  }
  sqlite3VdbeChangeEncoding(u.ch.pMem, encoding);

  const sqlite3_module *pModule;
  Mem *pDest;
  sqlite3_context sContext;
#endif /* local variables moved into u.co */

  VdbeCursor *pCur = p->apCsr[pOp->p1];
  assert( pCur->pVtabCursor );
  assert( pOp->p3>0 && pOp->p3<=(p->nMem-p->nCursor) );
  u.co.pDest = &aMem[pOp->p3];
  memAboutToChange(p, u.co.pDest);
  if( pCur->nullRow ){
    sqlite3VdbeMemSetNull(u.co.pDest);
    break;
  }
  u.co.pVtab = pCur->pVtabCursor->pVtab;

    case TK_UPLUS: {
      rc = sqlite3ExprIsInteger(p->pLeft, pValue);
      break;
    }
    case TK_UMINUS: {
      int v;
      if( sqlite3ExprIsInteger(p->pLeft, &v) ){
        assert( v!=(-2147483647-1) );
        *pValue = -v;
        rc = 1;
      }
      break;
    }
    default: break;
  }

    return;
  }

  /* Ensure the default expression is something that sqlite3ValueFromExpr()
  ** can handle (i.e. not CURRENT_TIME etc.)
  */
  if( pDflt ){
    sqlite3_value *pVal = 0;
    if( sqlite3ValueFromExpr(db, pDflt, SQLITE_UTF8, SQLITE_AFF_NONE, &pVal) ){
      db->mallocFailed = 1;
      return;
    }
    if( !pVal ){
      sqlite3ErrorMsg(pParse, "Cannot add a column with non-constant default");
      return;

  return;
}
#endif  /* SQLITE_ALTER_TABLE */

/************** End of alter.c ***********************************************/
/************** Begin file analyze.c *****************************************/
/*
** 2005-07-08
**
** The author disclaims copyright to this source code.  In place of
** a legal notice, here is a blessing:
**
**    May you do good and not evil.
**    May you find forgiveness for yourself and forgive others.
**    May you share freely, never taking more than you give.
**
*************************************************************************
** This file contains code associated with the ANALYZE command.
**
** The ANALYZE command gather statistics about the content of tables
** and indices.  These statistics are made available to the query planner
** to help it make better decisions about how to perform queries.
**
** The following system tables are or have been supported:
**
**    CREATE TABLE sqlite_stat1(tbl, idx, stat);
**    CREATE TABLE sqlite_stat2(tbl, idx, sampleno, sample);
**    CREATE TABLE sqlite_stat3(tbl, idx, nEq, nLt, nDLt, sample);
**    CREATE TABLE sqlite_stat4(tbl, idx, nEq, nLt, nDLt, sample);
**
** Additional tables might be added in future releases of SQLite.
** The sqlite_stat2 table is not created or used unless the SQLite version
** is between 3.6.18 and 3.7.8, inclusive, and unless SQLite is compiled
** with SQLITE_ENABLE_STAT2.  The sqlite_stat2 table is deprecated.
** The sqlite_stat2 table is superseded by sqlite_stat3, which is only
** created and used by SQLite versions 3.7.9 and later and with
** SQLITE_ENABLE_STAT3 defined.  The functionality of sqlite_stat3
** is a superset of sqlite_stat2.  The sqlite_stat4 is an enhanced
** version of sqlite_stat3 and is only available when compiled with
** SQLITE_ENABLE_STAT4 and in SQLite versions 3.8.0 and later.  It is
** not possible to enable both STAT3 and STAT4 at the same time.  If they
** are both enabled, then STAT4 is precedence.
**
** For most applications, sqlite_stat1 provides all the statisics required
** for the query planner to make good choices.
**
** Format of sqlite_stat1:
**
** There is normally one row per index, with the index identified by the
** name in the idx column.  The tbl column is the name of the table to
** which the index belongs.  In each such row, the stat column will be
** a string consisting of a list of integers.  The first integer in this
** list is the number of rows in the index.  (This is the same as the
** number of rows in the table, except for partial indices.)  The second
** integer is the average number of rows in the index that have the same
** value in the first column of the index.  The third integer is the average
** number of rows in the index that have the same value for the first two
** columns.  The N-th integer (for N>1) is the average number of rows in 
** the index which have the same value for the first N-1 columns.  For
** a K-column index, there will be K+1 integers in the stat column.  If
** the index is unique, then the last integer will be 1.

** The format for sqlite_stat2 is recorded here for legacy reference.  This
** version of SQLite does not support sqlite_stat2.  It neither reads nor
** writes the sqlite_stat2 table.  This version of SQLite only supports
** sqlite_stat3.
**
** Format for sqlite_stat3:
**
** The sqlite_stat3 format is a subset of sqlite_stat4.  Hence, the
** sqlite_stat4 format will be described first.  Further information
** about sqlite_stat3 follows the sqlite_stat4 description.
**
** Format for sqlite_stat4:
**
** As with sqlite_stat2, the sqlite_stat4 table contains histogram data
** to aid the query planner in choosing good indices based on the values
** that indexed columns are compared against in the WHERE clauses of
** queries.
**
** The sqlite_stat4 table contains multiple entries for each index.
** The idx column names the index and the tbl column is the table of the
** index.  If the idx and tbl columns are the same, then the sample is
** of the INTEGER PRIMARY KEY.  The sample column is a blob which is the
** binary encoding of a key from the index, with the trailing rowid
** omitted.  The nEq column is a list of integers.  The first integer
** is the approximate number of entries in the index whose left-most 
** column exactly matches the left-most column of the sample.  The second
** integer in nEq is the approximate number of entries in the index where
** the first two columns match the first two columns of the sample.
** And so forth.  nLt is another list of integers that show the approximate
** number of entries that are strictly less than the sample.  The first
** integer in nLt contains the number of entries in the index where the
** left-most column is less than the left-most column of the sample.
** The K-th integer in the nLt entry is the number of index entries 
** where the first K columns are less than the first K columns of the
** sample.  The nDLt column is like nLt except that it contains the 
** number of distinct entries in the index that are less than the
** sample.
**









** There can be an arbitrary number of sqlite_stat4 entries per index.
** The ANALYZE command will typically generate sqlite_stat4 tables
** that contain between 10 and 40 samples which are distributed across
** the key space, though not uniformly, and which include samples with
** large nEq values.
**
** Format for sqlite_stat3 redux:
**
** The sqlite_stat3 table is like sqlite_stat4 except that it only
** looks at the left-most column of the index.  The sqlite_stat3.sample
** column contains the actual value of the left-most column instead
** of a blob encoding of the complete index key as is found in
** sqlite_stat4.sample.  The nEq, nLt, and nDLt entries of sqlite_stat3
** all contain just a single integer which is the same as the first
** integer in the equivalent columns in sqlite_stat4.
*/
#ifndef SQLITE_OMIT_ANALYZE

#if defined(SQLITE_ENABLE_STAT4)
# define IsStat4     1
# define IsStat3     0
#elif defined(SQLITE_ENABLE_STAT3)
# define IsStat4     0
# define IsStat3     1
#else
# define IsStat4     0
# define IsStat3     0
# undef SQLITE_STAT4_SAMPLES
# define SQLITE_STAT4_SAMPLES 1
#endif
#define IsStat34    (IsStat3+IsStat4)  /* 1 for STAT3 or STAT4. 0 otherwise */

/*
** This routine generates code that opens the sqlite_statN tables.

** The sqlite_stat1 table is always relevant.  sqlite_stat2 is now
** obsolete.  sqlite_stat3 and sqlite_stat4 are only opened when
** appropriate compile-time options are provided.
**
** If the sqlite_statN tables do not previously exist, it is created.


**
** Argument zWhere may be a pointer to a buffer containing a table name,
** or it may be a NULL pointer. If it is not NULL, then all entries in

** the sqlite_statN tables associated with the named table are deleted.
** If zWhere==0, then code is generated to delete all stat table entries.
*/
static void openStatTable(
  Parse *pParse,          /* Parsing context */
  int iDb,                /* The database we are looking in */
  int iStatCur,           /* Open the sqlite_stat1 table on this cursor */
  const char *zWhere,     /* Delete entries for this table or index */
  const char *zWhereType  /* Either "tbl" or "idx" */
){
  static const struct {
    const char *zName;
    const char *zCols;
  } aTable[] = {
    { "sqlite_stat1", "tbl,idx,stat" },
#if defined(SQLITE_ENABLE_STAT4)
    { "sqlite_stat4", "tbl,idx,neq,nlt,ndlt,sample" },
    { "sqlite_stat3", 0 },
#elif defined(SQLITE_ENABLE_STAT3)
    { "sqlite_stat3", "tbl,idx,neq,nlt,ndlt,sample" },
    { "sqlite_stat4", 0 },
#else
    { "sqlite_stat3", 0 },
    { "sqlite_stat4", 0 },
#endif
  };




  int i;
  sqlite3 *db = pParse->db;
  Db *pDb;
  Vdbe *v = sqlite3GetVdbe(pParse);
  int aRoot[ArraySize(aTable)];
  u8 aCreateTbl[ArraySize(aTable)];

  if( v==0 ) return;
  assert( sqlite3BtreeHoldsAllMutexes(db) );
  assert( sqlite3VdbeDb(v)==db );
  pDb = &db->aDb[iDb];

  /* Create new statistic tables if they do not exist, or clear them
  ** if they do already exist.
  */
  for(i=0; i<ArraySize(aTable); i++){
    const char *zTab = aTable[i].zName;
    Table *pStat;
    if( (pStat = sqlite3FindTable(db, zTab, pDb->zName))==0 ){
      if( aTable[i].zCols ){
        /* The sqlite_statN table does not exist. Create it. Note that a 
        ** side-effect of the CREATE TABLE statement is to leave the rootpage 
        ** of the new table in register pParse->regRoot. This is important 
        ** because the OpenWrite opcode below will be needing it. */
        sqlite3NestedParse(pParse,
            "CREATE TABLE %Q.%s(%s)", pDb->zName, zTab, aTable[i].zCols
        );
        aRoot[i] = pParse->regRoot;
        aCreateTbl[i] = OPFLAG_P2ISREG;
      }
    }else{
      /* The table already exists. If zWhere is not NULL, delete all entries 
      ** associated with the table zWhere. If zWhere is NULL, delete the
      ** entire contents of the table. */
      aRoot[i] = pStat->tnum;
      aCreateTbl[i] = 0;
      sqlite3TableLock(pParse, iDb, aRoot[i], 1, zTab);
      if( zWhere ){
        sqlite3NestedParse(pParse,
           "DELETE FROM %Q.%s WHERE %s=%Q",
           pDb->zName, zTab, zWhereType, zWhere
        );
      }else{
        /* The sqlite_stat[134] table already exists.  Delete all rows. */
        sqlite3VdbeAddOp2(v, OP_Clear, aRoot[i], iDb);
      }
    }
  }

  /* Open the sqlite_stat[134] tables for writing. */
  for(i=0; aTable[i].zCols; i++){
    assert( i<ArraySize(aTable) );
    sqlite3VdbeAddOp3(v, OP_OpenWrite, iStatCur+i, aRoot[i], iDb);
    sqlite3VdbeChangeP4(v, -1, (char *)3, P4_INT32);
    sqlite3VdbeChangeP5(v, aCreateTbl[i]);
  }
}

/*
** Recommended number of samples for sqlite_stat4
*/
#ifndef SQLITE_STAT4_SAMPLES
# define SQLITE_STAT4_SAMPLES 24
#endif

/*
** Three SQL functions - stat_init(), stat_push(), and stat_get() -
** share an instance of the following structure to hold their state
** information.
*/
typedef struct Stat4Accum Stat4Accum;
typedef struct Stat4Sample Stat4Sample;
struct Stat4Sample {
  tRowcnt *anEq;                  /* sqlite_stat4.nEq */
  tRowcnt *anDLt;                 /* sqlite_stat4.nDLt */
#ifdef SQLITE_ENABLE_STAT3_OR_STAT4
  tRowcnt *anLt;                  /* sqlite_stat4.nLt */
  i64 iRowid;                     /* Rowid in main table of the key */
  u8 isPSample;                   /* True if a periodic sample */
  int iCol;                       /* If !isPSample, the reason for inclusion */
  u32 iHash;                      /* Tiebreaker hash */
#endif
};                                                    
struct Stat4Accum {
  tRowcnt nRow;             /* Number of rows in the entire table */
  tRowcnt nPSample;         /* How often to do a periodic sample */
  int nCol;                 /* Number of columns in index + rowid */
  int mxSample;             /* Maximum number of samples to accumulate */
  Stat4Sample current;      /* Current row as a Stat4Sample */
  u32 iPrn;                 /* Pseudo-random number used for sampling */


  Stat4Sample *aBest;       /* Array of (nCol-1) best samples */
  int iMin;                 /* Index in a[] of entry with minimum score */

  int nSample;              /* Current number of samples */
  int iGet;                 /* Index of current sample accessed by stat_get() */
  Stat4Sample *a;           /* Array of mxSample Stat4Sample objects */
};


/*
** Implementation of the stat_init(N,C) SQL function. The two parameters
** are the number of rows in the table or index (C) and the number of columns

** in the index (N).  The second argument (C) is only used for STAT3 and STAT4.
**
** This routine allocates the Stat4Accum object in heap memory. The return 

** value is a pointer to the the Stat4Accum object encoded as a blob (i.e. 
** the size of the blob is sizeof(void*) bytes). 
*/
static void statInit(
  sqlite3_context *context,
  int argc,
  sqlite3_value **argv
){
  Stat4Accum *p;
  int nCol;                       /* Number of columns in index being sampled */
  int nColUp;                     /* nCol rounded up for alignment */
  int n;                          /* Bytes of space to allocate */
#ifdef SQLITE_ENABLE_STAT3_OR_STAT4
  int mxSample = SQLITE_STAT4_SAMPLES;
#endif

  /* Decode the three function arguments */
  UNUSED_PARAMETER(argc);
  nCol = sqlite3_value_int(argv[0]);
  assert( nCol>1 );               /* >1 because it includes the rowid column */
  nColUp = sizeof(tRowcnt)<8 ? (nCol+1)&~1 : nCol;

  /* Allocate the space required for the Stat4Accum object */
  n = sizeof(*p) 
    + sizeof(tRowcnt)*nColUp                  /* Stat4Accum.anEq */
    + sizeof(tRowcnt)*nColUp                  /* Stat4Accum.anDLt */
#ifdef SQLITE_ENABLE_STAT3_OR_STAT4
    + sizeof(tRowcnt)*nColUp                  /* Stat4Accum.anLt */
    + sizeof(Stat4Sample)*(nCol+mxSample)   /* Stat4Accum.aBest[], a[] */
    + sizeof(tRowcnt)*3*nColUp*(nCol+mxSample)
#endif
  ;
  p = sqlite3MallocZero(n);
  if( p==0 ){
    sqlite3_result_error_nomem(context);
    return;
  }

  p->nRow = 0;
  p->nCol = nCol;
  p->current.anDLt = (tRowcnt*)&p[1];
  p->current.anEq = &p->current.anDLt[nColUp];

#ifdef SQLITE_ENABLE_STAT3_OR_STAT4
  {
    u8 *pSpace;                     /* Allocated space not yet assigned */
    int i;                          /* Used to iterate through p->aSample[] */

    p->iGet = -1;
    p->mxSample = mxSample;
    p->nPSample = sqlite3_value_int64(argv[1])/(mxSample/3+1) + 1;
    p->current.anLt = &p->current.anEq[nColUp];
    sqlite3_randomness(sizeof(p->iPrn), &p->iPrn);
  
    /* Set up the Stat4Accum.a[] and aBest[] arrays */
    p->a = (struct Stat4Sample*)&p->current.anLt[nColUp];
    p->aBest = &p->a[mxSample];
    pSpace = (u8*)(&p->a[mxSample+nCol]);
    for(i=0; i<(mxSample+nCol); i++){
      p->a[i].anEq = (tRowcnt *)pSpace; pSpace += (sizeof(tRowcnt) * nColUp);
      p->a[i].anLt = (tRowcnt *)pSpace; pSpace += (sizeof(tRowcnt) * nColUp);
      p->a[i].anDLt = (tRowcnt *)pSpace; pSpace += (sizeof(tRowcnt) * nColUp);
    }
    assert( (pSpace - (u8*)p)==n );
  
    for(i=0; i<nCol; i++){
      p->aBest[i].iCol = i;
    }
  }
#endif

  /* Return a pointer to the allocated object to the caller */
  sqlite3_result_blob(context, p, sizeof(p), sqlite3_free);
}
static const FuncDef statInitFuncdef = {
  1+IsStat34,      /* nArg */
  SQLITE_UTF8,     /* iPrefEnc */
  0,               /* flags */
  0,               /* pUserData */
  0,               /* pNext */
  statInit,        /* xFunc */
  0,               /* xStep */
  0,               /* xFinalize */
  "stat_init",     /* zName */
  0,               /* pHash */
  0                /* pDestructor */
};

#ifdef SQLITE_ENABLE_STAT3_OR_STAT4
/*
** Return true if pNew is to be preferred over pOld.
*/
static int sampleIsBetter(Stat4Sample *pNew, Stat4Sample *pOld){
  tRowcnt nEqNew = pNew->anEq[pNew->iCol];
  tRowcnt nEqOld = pOld->anEq[pOld->iCol];

  assert( pOld->isPSample==0 && pNew->isPSample==0 );
  assert( IsStat4 || (pNew->iCol==0 && pOld->iCol==0) );

  if( (nEqNew>nEqOld)
   || (nEqNew==nEqOld && pNew->iCol<pOld->iCol)
   || (nEqNew==nEqOld && pNew->iCol==pOld->iCol && pNew->iHash>pOld->iHash)
  ){
    return 1;
  }
  return 0;
}

/*



** Copy the contents of object (*pFrom) into (*pTo).


*/
void sampleCopy(Stat4Accum *p, Stat4Sample *pTo, Stat4Sample *pFrom){








  pTo->iRowid = pFrom->iRowid;
  pTo->isPSample = pFrom->isPSample;
  pTo->iCol = pFrom->iCol;
  pTo->iHash = pFrom->iHash;



  memcpy(pTo->anEq, pFrom->anEq, sizeof(tRowcnt)*p->nCol);
  memcpy(pTo->anLt, pFrom->anLt, sizeof(tRowcnt)*p->nCol);
  memcpy(pTo->anDLt, pFrom->anDLt, sizeof(tRowcnt)*p->nCol);
}

/*
** Copy the contents of sample *pNew into the p->a[] array. If necessary,
** remove the least desirable sample from p->a[] to make room.
*/
static void sampleInsert(Stat4Accum *p, Stat4Sample *pNew, int nEqZero){
  Stat4Sample *pSample;
  int i;
  i64 iSeq;
  i64 iPos;

  assert( IsStat4 || nEqZero==0 );


  if( pNew->isPSample==0 ){
    Stat4Sample *pUpgrade = 0;
    assert( pNew->anEq[pNew->iCol]>0 );

    /* This sample is being added because the prefix that ends in column 
    ** iCol occurs many times in the table. However, if we have already
    ** added a sample that shares this prefix, there is no need to add
    ** this one. Instead, upgrade the priority of the highest priority
    ** existing sample that shares this prefix.  */
    for(i=p->nSample-1; i>=0; i--){
      Stat4Sample *pOld = &p->a[i];
      if( pOld->anEq[pNew->iCol]==0 ){
        if( pOld->isPSample ) return;
        assert( sampleIsBetter(pNew, pOld) );
        if( pUpgrade==0 || sampleIsBetter(pOld, pUpgrade) ){
          pUpgrade = pOld;
        }
      }
    }
    if( pUpgrade ){
      pUpgrade->iCol = pNew->iCol;
      pUpgrade->anEq[pUpgrade->iCol] = pNew->anEq[pUpgrade->iCol];
      goto find_new_min;
    }
  }

  /* If necessary, remove sample iMin to make room for the new sample. */
  if( p->nSample>=p->mxSample ){
    Stat4Sample *pMin = &p->a[p->iMin];
    tRowcnt *anEq = pMin->anEq;
    tRowcnt *anLt = pMin->anLt;
    tRowcnt *anDLt = pMin->anDLt;
    memmove(pMin, &pMin[1], sizeof(p->a[0])*(p->nSample-p->iMin-1));
    pSample = &p->a[p->nSample-1];
    pSample->anEq = anEq;
    pSample->anDLt = anDLt;
    pSample->anLt = anLt;
    p->nSample = p->mxSample-1;
  }

  /* Figure out where in the a[] array the new sample should be inserted. */
  iSeq = pNew->anLt[p->nCol-1];

  for(iPos=p->nSample; iPos>0; iPos--){

    if( iSeq>p->a[iPos-1].anLt[p->nCol-1] ) break;
  }

  /* Insert the new sample */
  pSample = &p->a[iPos];

  if( iPos!=p->nSample ){

    Stat4Sample *pEnd = &p->a[p->nSample];
    tRowcnt *anEq = pEnd->anEq;
    tRowcnt *anLt = pEnd->anLt;
    tRowcnt *anDLt = pEnd->anDLt;
    memmove(&p->a[iPos], &p->a[iPos+1], (p->nSample-iPos)*sizeof(p->a[0]));
    pSample->anEq = anEq;
    pSample->anDLt = anDLt;
    pSample->anLt = anLt;
  }
  p->nSample++;
  sampleCopy(p, pSample, pNew);

  /* Zero the first nEqZero entries in the anEq[] array. */
  memset(pSample->anEq, 0, sizeof(tRowcnt)*nEqZero);

 find_new_min:
  if( p->nSample>=p->mxSample ){
    int iMin = -1;
    for(i=0; i<p->mxSample; i++){
      if( p->a[i].isPSample ) continue;
      if( iMin<0 || sampleIsBetter(&p->a[iMin], &p->a[i]) ){


        iMin = i;


      }
    }
    assert( iMin>=0 );
    p->iMin = iMin;
  }
}
#endif /* SQLITE_ENABLE_STAT3_OR_STAT4 */

/*
** Field iChng of the index being scanned has changed. So at this point
** p->current contains a sample that reflects the previous row of the
** index. The value of anEq[iChng] and subsequent anEq[] elements are
** correct at this point.
*/
static void samplePushPrevious(Stat4Accum *p, int iChng){
#ifdef SQLITE_ENABLE_STAT4
  int i;

  /* Check if any samples from the aBest[] array should be pushed
  ** into IndexSample.a[] at this point.  */
  for(i=(p->nCol-2); i>=iChng; i--){
    Stat4Sample *pBest = &p->aBest[i];
    if( p->nSample<p->mxSample
     || sampleIsBetter(pBest, &p->a[p->iMin])
    ){
      sampleInsert(p, pBest, i);
    }
  }

  /* Update the anEq[] fields of any samples already collected. */
  for(i=p->nSample-1; i>=0; i--){
    int j;
    for(j=iChng; j<p->nCol; j++){
      if( p->a[i].anEq[j]==0 ) p->a[i].anEq[j] = p->current.anEq[j];
    }
  }
#endif

#if defined(SQLITE_ENABLE_STAT3) && !defined(SQLITE_ENABLE_STAT4)
  if( iChng==0 ){
    tRowcnt nLt = p->current.anLt[0];
    tRowcnt nEq = p->current.anEq[0];

    /* Check if this is to be a periodic sample. If so, add it. */
    if( (nLt/p->nPSample)!=(nLt+nEq)/p->nPSample ){
      p->current.isPSample = 1;
      sampleInsert(p, &p->current, 0);
      p->current.isPSample = 0;
    }else 

    /* Or if it is a non-periodic sample. Add it in this case too. */
    if( p->nSample<p->mxSample || sampleIsBetter(&p->current, &p->a[p->iMin]) ){
      sampleInsert(p, &p->current, 0);
    }
  }
#endif
}

/*
** Implementation of the stat_push SQL function:  stat_push(P,R,C)
** Arguments:
**
**    P     Pointer to the Stat4Accum object created by stat_init()
**    C     Index of left-most column to differ from previous row
**    R     Rowid for the current row
**
** The SQL function always returns NULL.
**
** The R parameter is only used for STAT3 and STAT4.
*/
static void statPush(
  sqlite3_context *context,
  int argc,
  sqlite3_value **argv
){
  int i;

  /* The three function arguments */
  Stat4Accum *p = (Stat4Accum*)sqlite3_value_blob(argv[0]);
  int iChng = sqlite3_value_int(argv[1]);

  assert( p->nCol>1 );        /* Includes rowid field */
  assert( iChng<p->nCol );

  if( p->nRow==0 ){
    /* anEq[0] is only zero for the very first call to this function.  Do
    ** appropriate initialization */
    for(i=0; i<p->nCol; i++) p->current.anEq[i] = 1;
  }else{
    /* Second and subsequent calls get processed here */
    samplePushPrevious(p, iChng);

    /* Update anDLt[], anLt[] and anEq[] to reflect the values that apply
    ** to the current row of the index. */
    for(i=0; i<iChng; i++){
      p->current.anEq[i]++;
    }
    for(i=iChng; i<p->nCol; i++){
      p->current.anDLt[i]++;
#ifdef SQLITE_ENABLE_STAT3_OR_STAT4
      p->current.anLt[i] += p->current.anEq[i];
#endif
      p->current.anEq[i] = 1;
    }
  }
  p->nRow++;
#ifdef SQLITE_ENABLE_STAT3_OR_STAT4
  p->current.iRowid = sqlite3_value_int64(argv[2]);
  p->current.iHash = p->iPrn = p->iPrn*1103515245 + 12345;
#endif

#ifdef SQLITE_ENABLE_STAT4
  {
    tRowcnt nLt = p->current.anLt[p->nCol-1];

    /* Check if this is to be a periodic sample. If so, add it. */
    if( (nLt/p->nPSample)!=(nLt+1)/p->nPSample ){
      p->current.isPSample = 1;
      p->current.iCol = 0;
      sampleInsert(p, &p->current, p->nCol-1);
      p->current.isPSample = 0;
    }

    /* Update the aBest[] array. */
    for(i=0; i<(p->nCol-1); i++){
      p->current.iCol = i;
      if( i>=iChng || sampleIsBetter(&p->current, &p->aBest[i]) ){
        sampleCopy(p, &p->aBest[i], &p->current);
      }
    }
  }
#endif
}
static const FuncDef statPushFuncdef = {
  2+IsStat34,      /* nArg */
  SQLITE_UTF8,     /* iPrefEnc */
  0,               /* flags */
  0,               /* pUserData */
  0,               /* pNext */
  statPush,        /* xFunc */
  0,               /* xStep */
  0,               /* xFinalize */
  "stat_push",     /* zName */
  0,               /* pHash */
  0                /* pDestructor */
};

#define STAT_GET_STAT1 0          /* "stat" column of stat1 table */
#define STAT_GET_ROWID 1          /* "rowid" column of stat[34] entry */
#define STAT_GET_NEQ   2          /* "neq" column of stat[34] entry */
#define STAT_GET_NLT   3          /* "nlt" column of stat[34] entry */
#define STAT_GET_NDLT  4          /* "ndlt" column of stat[34] entry */

/*
** Implementation of the stat_get(P,J) SQL function.  This routine is
** used to query the results.  Content is returned for parameter J


** which is one of the STAT_GET_xxxx values defined above.
**
** If neither STAT3 nor STAT4 are enabled, then J is always
** STAT_GET_STAT1 and is hence omitted and this routine becomes
** a one-parameter function, stat_get(P), that always returns the
** stat1 table entry information.



*/
static void statGet(
  sqlite3_context *context,
  int argc,
  sqlite3_value **argv
){
  Stat4Accum *p = (Stat4Accum*)sqlite3_value_blob(argv[0]);
#ifdef SQLITE_ENABLE_STAT3_OR_STAT4
  /* STAT3 and STAT4 have a parameter on this routine. */
  int eCall = sqlite3_value_int(argv[1]);
  assert( argc==2 );
  assert( eCall==STAT_GET_STAT1 || eCall==STAT_GET_NEQ 
       || eCall==STAT_GET_ROWID || eCall==STAT_GET_NLT
       || eCall==STAT_GET_NDLT 
  );
  if( eCall==STAT_GET_STAT1 )
#else
  assert( argc==1 );
#endif
  {
    /* Return the value to store in the "stat" column of the sqlite_stat1
    ** table for this index.
    **
    ** The value is a string composed of a list of integers describing 
    ** the index. The first integer in the list is the total number of 
    ** entries in the index. There is one additional integer in the list 
    ** for each indexed column. This additional integer is an estimate of
    ** the number of rows matched by a stabbing query on the index using
    ** a key with the corresponding number of fields. In other words,
    ** if the index is on columns (a,b) and the sqlite_stat1 value is 
    ** "100 10 2", then SQLite estimates that:
    **
    **   * the index contains 100 rows,
    **   * "WHERE a=?" matches 10 rows, and
    **   * "WHERE a=? AND b=?" matches 2 rows.
    **
    ** If D is the count of distinct values and K is the total number of 
    ** rows, then each estimate is computed as:
    **
    **        I = (K+D-1)/D
    */
    char *z;
    int i;

    char *zRet = sqlite3MallocZero(p->nCol * 25);
    if( zRet==0 ){
      sqlite3_result_error_nomem(context);
      return;
    }

    sqlite3_snprintf(24, zRet, "%lld", p->nRow);
    z = zRet + sqlite3Strlen30(zRet);
    for(i=0; i<(p->nCol-1); i++){
      i64 nDistinct = p->current.anDLt[i] + 1;
      i64 iVal = (p->nRow + nDistinct - 1) / nDistinct;
      sqlite3_snprintf(24, z, " %lld", iVal);
      z += sqlite3Strlen30(z);
      assert( p->current.anEq[i] );
    }
    assert( z[0]=='\0' && z>zRet );

    sqlite3_result_text(context, zRet, -1, sqlite3_free);
  }
#ifdef SQLITE_ENABLE_STAT3_OR_STAT4
  else if( eCall==STAT_GET_ROWID ){
    if( p->iGet<0 ){
      samplePushPrevious(p, 0);
      p->iGet = 0;
    }
    if( p->iGet<p->nSample ){

      sqlite3_result_int64(context, p->a[p->iGet].iRowid);
    }
  }else{
    tRowcnt *aCnt = 0;

    assert( p->iGet<p->nSample );
    switch( eCall ){
      case STAT_GET_NEQ:  aCnt = p->a[p->iGet].anEq; break;
      case STAT_GET_NLT:  aCnt = p->a[p->iGet].anLt; break;
      default: {
        aCnt = p->a[p->iGet].anDLt; 
        p->iGet++;
        break;
      }
    }






    if( IsStat3 ){



      sqlite3_result_int64(context, (i64)aCnt[0]);

    }else{
      char *zRet = sqlite3MallocZero(p->nCol * 25);
      if( zRet==0 ){
        sqlite3_result_error_nomem(context);
      }else{
        int i;
        char *z = zRet;
        for(i=0; i<p->nCol; i++){
          sqlite3_snprintf(24, z, "%lld ", aCnt[i]);
          z += sqlite3Strlen30(z);
        }
        assert( z[0]=='\0' && z>zRet );
        z[-1] = '\0';
        sqlite3_result_text(context, zRet, -1, sqlite3_free);
      }
    }
  }
#endif /* SQLITE_ENABLE_STAT3_OR_STAT4 */
}
static const FuncDef statGetFuncdef = {
  1+IsStat34,      /* nArg */
  SQLITE_UTF8,     /* iPrefEnc */
  0,               /* flags */
  0,               /* pUserData */
  0,               /* pNext */
  statGet,         /* xFunc */
  0,               /* xStep */
  0,               /* xFinalize */
  "stat_get",      /* zName */
  0,               /* pHash */
  0                /* pDestructor */
};

static void callStatGet(Vdbe *v, int regStat4, int iParam, int regOut){
  assert( regOut!=regStat4 && regOut!=regStat4+1 );
#ifdef SQLITE_ENABLE_STAT3_OR_STAT4
  sqlite3VdbeAddOp2(v, OP_Integer, iParam, regStat4+1);
#else
  assert( iParam==STAT_GET_STAT1 );
#endif
  sqlite3VdbeAddOp3(v, OP_Function, 0, regStat4, regOut);
  sqlite3VdbeChangeP4(v, -1, (char*)&statGetFuncdef, P4_FUNCDEF);
  sqlite3VdbeChangeP5(v, 1 + IsStat34);
}

/*
** Generate code to do an analysis of all indices associated with
** a single table.
*/
static void analyzeOneTable(
  Parse *pParse,   /* Parser context */
  Table *pTab,     /* Table whose indices are to be analyzed */
  Index *pOnlyIdx, /* If not NULL, only analyze this one index */
  int iStatCur,    /* Index of VdbeCursor that writes the sqlite_stat1 table */
  int iMem,        /* Available memory locations begin here */
  int iTab         /* Next available cursor */
){
  sqlite3 *db = pParse->db;    /* Database handle */
  Index *pIdx;                 /* An index to being analyzed */
  int iIdxCur;                 /* Cursor open on index being analyzed */
  int iTabCur;                 /* Table cursor */
  Vdbe *v;                     /* The virtual machine being built up */
  int i;                       /* Loop counter */


  int jZeroRows = -1;          /* Jump from here if number of rows is zero */
  int iDb;                     /* Index of database containing pTab */
  u8 needTableCnt = 1;         /* True to count the table */
  int regNewRowid = iMem++;    /* Rowid for the inserted record */
  int regStat4 = iMem++;       /* Register to hold Stat4Accum object */
  int regChng = iMem++;        /* Index of changed index field */
#ifdef SQLITE_ENABLE_STAT3_OR_STAT4








  int regRowid = iMem++;       /* Rowid argument passed to stat_push() */




#endif


  int regTemp = iMem++;        /* Temporary use register */
  int regTabname = iMem++;     /* Register containing table name */
  int regIdxname = iMem++;     /* Register containing index name */
  int regStat1 = iMem++;       /* Value for the stat column of sqlite_stat1 */
  int regPrev = iMem;          /* MUST BE LAST (see below) */

  pParse->nMem = MAX(pParse->nMem, iMem);
  v = sqlite3GetVdbe(pParse);
  if( v==0 || NEVER(pTab==0) ){
    return;
  }
  if( pTab->tnum==0 ){
    /* Do not gather statistics on views or virtual tables */
    return;

#ifndef SQLITE_OMIT_AUTHORIZATION
  if( sqlite3AuthCheck(pParse, SQLITE_ANALYZE, pTab->zName, 0,
      db->aDb[iDb].zName ) ){
    return;
  }
#endif

  /* Establish a read-lock on the table at the shared-cache level. 
  ** Open a read-only cursor on the table. Also allocate a cursor number
  ** to use for scanning indexes (iIdxCur). No index cursor is opened at
  ** this time though.  */
  sqlite3TableLock(pParse, iDb, pTab->tnum, 0, pTab->zName);
  iTabCur = iTab++;
  iIdxCur = iTab++;
  pParse->nTab = MAX(pParse->nTab, iTab);
  sqlite3OpenTable(pParse, iTabCur, iDb, pTab, OP_OpenRead);
  sqlite3VdbeAddOp4(v, OP_String8, 0, regTabname, 0, pTab->zName, 0);

  for(pIdx=pTab->pIndex; pIdx; pIdx=pIdx->pNext){
    int nCol;                     /* Number of columns indexed by pIdx */
    KeyInfo *pKey;                /* KeyInfo structure for pIdx */

    int *aGotoChng;               /* Array of jump instruction addresses */
    int addrRewind;               /* Address of "OP_Rewind iIdxCur" */
    int addrGotoChng0;            /* Address of "Goto addr_chng_0" */
    int addrNextRow;              /* Address of "next_row:" */

    if( pOnlyIdx && pOnlyIdx!=pIdx ) continue;
    if( pIdx->pPartIdxWhere==0 ) needTableCnt = 0;
    VdbeNoopComment((v, "Begin analysis of %s", pIdx->zName));
    nCol = pIdx->nColumn;
    aGotoChng = sqlite3DbMallocRaw(db, sizeof(int)*(nCol+1));
    if( aGotoChng==0 ) continue;
    pKey = sqlite3IndexKeyinfo(pParse, pIdx);










    /* Populate the register containing the index name. */
    sqlite3VdbeAddOp4(v, OP_String8, 0, regIdxname, 0, pIdx->zName, 0);


    /*
    ** Pseudo-code for loop that calls stat_push():
    **
    **   Rewind csr
    **   if eof(csr) goto end_of_scan;
    **   regChng = 0



    **   goto chng_addr_0;

    **
    **  next_row:
    **   regChng = 0
    **   if( idx(0) != regPrev(0) ) goto chng_addr_0
    **   regChng = 1
    **   if( idx(1) != regPrev(1) ) goto chng_addr_1
    **   ...
    **   regChng = N
    **   goto chng_addr_N

    **
    **  chng_addr_0:
    **   regPrev(0) = idx(0)
    **  chng_addr_1:
    **   regPrev(1) = idx(1)
    **  ...
    **
    **  chng_addr_N:
    **   regRowid = idx(rowid)

    **   stat_push(P, regChng, regRowid)
    **   Next csr
    **   if !eof(csr) goto next_row;

    **

    **  end_of_scan:
    */

    /* Make sure there are enough memory cells allocated to accommodate 
    ** the regPrev array and a trailing rowid (the rowid slot is required
    ** when building a record to insert into the sample column of 
    ** the sqlite_stat4 table.  */
    pParse->nMem = MAX(pParse->nMem, regPrev+nCol);


    /* Open a read-only cursor on the index being analyzed. */
    assert( iDb==sqlite3SchemaToIndex(db, pIdx->pSchema) );
    sqlite3VdbeAddOp3(v, OP_OpenRead, iIdxCur, pIdx->tnum, iDb);
    sqlite3VdbeChangeP4(v, -1, (char*)pKey, P4_KEYINFO_HANDOFF); 
    VdbeComment((v, "%s", pIdx->zName));

    /* Invoke the stat_init() function. The arguments are:
    ** 
    **    (1) the number of columns in the index including the rowid,
    **    (2) the number of rows in the index,
    **
    ** The second argument is only used for STAT3 and STAT4
    */
#ifdef SQLITE_ENABLE_STAT3_OR_STAT4
    sqlite3VdbeAddOp2(v, OP_Count, iIdxCur, regStat4+2);
#endif
    sqlite3VdbeAddOp2(v, OP_Integer, nCol+1, regStat4+1);
    sqlite3VdbeAddOp3(v, OP_Function, 0, regStat4+1, regStat4);
    sqlite3VdbeChangeP4(v, -1, (char*)&statInitFuncdef, P4_FUNCDEF);
    sqlite3VdbeChangeP5(v, 1+IsStat34);


    /* Implementation of the following:
    **
    **   Rewind csr
    **   if eof(csr) goto end_of_scan;
    **   regChng = 0
    **   goto next_push_0;
    **
    */
    addrRewind = sqlite3VdbeAddOp1(v, OP_Rewind, iIdxCur);
    sqlite3VdbeAddOp2(v, OP_Integer, 0, regChng);
    addrGotoChng0 = sqlite3VdbeAddOp0(v, OP_Goto);


    /*
    **  next_row:
    **   regChng = 0
    **   if( idx(0) != regPrev(0) ) goto chng_addr_0
    **   regChng = 1
    **   if( idx(1) != regPrev(1) ) goto chng_addr_1
    **   ...
    **   regChng = N
    **   goto chng_addr_N
    */
    addrNextRow = sqlite3VdbeCurrentAddr(v);
    for(i=0; i<nCol; i++){
      char *pColl = (char*)sqlite3LocateCollSeq(pParse, pIdx->azColl[i]);
      sqlite3VdbeAddOp2(v, OP_Integer, i, regChng);
      sqlite3VdbeAddOp3(v, OP_Column, iIdxCur, i, regTemp);





      aGotoChng[i] = 

      sqlite3VdbeAddOp4(v, OP_Ne, regTemp, 0, regPrev+i, pColl, P4_COLLSEQ);

      sqlite3VdbeChangeP5(v, SQLITE_NULLEQ);





    }

    sqlite3VdbeAddOp2(v, OP_Integer, nCol, regChng);
    aGotoChng[nCol] = sqlite3VdbeAddOp0(v, OP_Goto);

    /*
    **  chng_addr_0:
    **   regPrev(0) = idx(0)
    **  chng_addr_1:
    **   regPrev(1) = idx(1)
    **  ...
    */
    sqlite3VdbeJumpHere(v, addrGotoChng0);
    for(i=0; i<nCol; i++){


      sqlite3VdbeJumpHere(v, aGotoChng[i]);











      sqlite3VdbeAddOp3(v, OP_Column, iIdxCur, i, regPrev+i);
    }


    /*
    **  chng_addr_N:
    **   regRowid = idx(rowid)            // STAT34 only
    **   stat_push(P, regChng, regRowid)  // 3rd parameter STAT34 only
    **   Next csr
    **   if !eof(csr) goto next_row;
    */
    sqlite3VdbeJumpHere(v, aGotoChng[nCol]);
#ifdef SQLITE_ENABLE_STAT3_OR_STAT4
    sqlite3VdbeAddOp2(v, OP_IdxRowid, iIdxCur, regRowid);
    assert( regRowid==(regStat4+2) );
#endif
    assert( regChng==(regStat4+1) );
    sqlite3VdbeAddOp3(v, OP_Function, 1, regStat4, regTemp);
    sqlite3VdbeChangeP4(v, -1, (char*)&statPushFuncdef, P4_FUNCDEF);
    sqlite3VdbeChangeP5(v, 2+IsStat34);
    sqlite3VdbeAddOp2(v, OP_Next, iIdxCur, addrNextRow);

    /* Add the entry to the stat1 table. */
    callStatGet(v, regStat4, STAT_GET_STAT1, regStat1);
    sqlite3VdbeAddOp4(v, OP_MakeRecord, regTabname, 3, regTemp, "aaa", 0);


    sqlite3VdbeAddOp2(v, OP_NewRowid, iStatCur, regNewRowid);
    sqlite3VdbeAddOp3(v, OP_Insert, iStatCur, regTemp, regNewRowid);




    sqlite3VdbeChangeP5(v, OPFLAG_APPEND);

    /* Add the entries to the stat3 or stat4 table. */
#ifdef SQLITE_ENABLE_STAT3_OR_STAT4
    {
      int regEq = regStat1;
      int regLt = regStat1+1;

      int regDLt = regStat1+2;
      int regSample = regStat1+3;
      int regCol = regStat1+4;
      int regSampleRowid = regCol + nCol;
      int addrNext;
      int addrIsNull;

      pParse->nMem = MAX(pParse->nMem, regCol+nCol+1);













      addrNext = sqlite3VdbeCurrentAddr(v);



      callStatGet(v, regStat4, STAT_GET_ROWID, regSampleRowid);
      addrIsNull = sqlite3VdbeAddOp1(v, OP_IsNull, regSampleRowid);
      callStatGet(v, regStat4, STAT_GET_NEQ, regEq);
      callStatGet(v, regStat4, STAT_GET_NLT, regLt);
      callStatGet(v, regStat4, STAT_GET_NDLT, regDLt);
      sqlite3VdbeAddOp3(v, OP_NotExists, iTabCur, addrNext, regSampleRowid);
#ifdef SQLITE_ENABLE_STAT3
      sqlite3ExprCodeGetColumnOfTable(v, pTab, iTabCur, 
                                      pIdx->aiColumn[0], regSample);
#else
      for(i=0; i<nCol; i++){



        int iCol = pIdx->aiColumn[i];

        sqlite3ExprCodeGetColumnOfTable(v, pTab, iTabCur, iCol, regCol+i);

      }
      sqlite3VdbeAddOp3(v, OP_MakeRecord, regCol, nCol+1, regSample);
#endif
      sqlite3VdbeAddOp4(v, OP_MakeRecord, regTabname, 6, regTemp, "bbbbbb", 0);
      sqlite3VdbeAddOp2(v, OP_NewRowid, iStatCur+1, regNewRowid);
      sqlite3VdbeAddOp3(v, OP_Insert, iStatCur+1, regTemp, regNewRowid);
      sqlite3VdbeAddOp2(v, OP_Goto, 0, addrNext);
      sqlite3VdbeJumpHere(v, addrIsNull);
    }
#endif /* SQLITE_ENABLE_STAT3_OR_STAT4 */

    /* End of analysis */
    sqlite3VdbeJumpHere(v, addrRewind);
    sqlite3DbFree(db, aGotoChng);
  }


  /* Create a single sqlite_stat1 entry containing NULL as the index
  ** name and the row count as the content.
  */
  if( pOnlyIdx==0 && needTableCnt ){

    VdbeComment((v, "%s", pTab->zName));
    sqlite3VdbeAddOp2(v, OP_Count, iTabCur, regStat1);

    jZeroRows = sqlite3VdbeAddOp1(v, OP_IfNot, regStat1);
    sqlite3VdbeAddOp2(v, OP_Null, 0, regIdxname);
    sqlite3VdbeAddOp4(v, OP_MakeRecord, regTabname, 3, regTemp, "aaa", 0);
    sqlite3VdbeAddOp2(v, OP_NewRowid, iStatCur, regNewRowid);
    sqlite3VdbeAddOp3(v, OP_Insert, iStatCur, regTemp, regNewRowid);
    sqlite3VdbeChangeP5(v, OPFLAG_APPEND);
    sqlite3VdbeJumpHere(v, jZeroRows);
  }

}


/*
** Generate code that will cause the most recent index analysis to
** be loaded into internal hash tables where is can be used.
*/

*/
static void analyzeDatabase(Parse *pParse, int iDb){
  sqlite3 *db = pParse->db;
  Schema *pSchema = db->aDb[iDb].pSchema;    /* Schema of database iDb */
  HashElem *k;
  int iStatCur;
  int iMem;
  int iTab;

  sqlite3BeginWriteOperation(pParse, 0, iDb);
  iStatCur = pParse->nTab;
  pParse->nTab += 3;
  openStatTable(pParse, iDb, iStatCur, 0, 0);
  iMem = pParse->nMem+1;
  iTab = pParse->nTab;
  assert( sqlite3SchemaMutexHeld(db, iDb, 0) );
  for(k=sqliteHashFirst(&pSchema->tblHash); k; k=sqliteHashNext(k)){
    Table *pTab = (Table*)sqliteHashData(k);
    analyzeOneTable(pParse, pTab, 0, iStatCur, iMem, iTab);
  }
  loadAnalysis(pParse, iDb);
}

/*
** Generate code that will do an analysis of a single table in
** a database.  If pOnlyIdx is not NULL then it is a single index

  iStatCur = pParse->nTab;
  pParse->nTab += 3;
  if( pOnlyIdx ){
    openStatTable(pParse, iDb, iStatCur, pOnlyIdx->zName, "idx");
  }else{
    openStatTable(pParse, iDb, iStatCur, pTab->zName, "tbl");
  }
  analyzeOneTable(pParse, pTab, pOnlyIdx, iStatCur,pParse->nMem+1,pParse->nTab);
  loadAnalysis(pParse, iDb);
}

/*
** Generate code for the ANALYZE command.  The parser calls this routine
** when it recognizes an ANALYZE command.
**

** callback routine.
*/
typedef struct analysisInfo analysisInfo;
struct analysisInfo {
  sqlite3 *db;
  const char *zDatabase;
};

/*
** The first argument points to a nul-terminated string containing a
** list of space separated integers. Read the first nOut of these into
** the array aOut[].
*/
static void decodeIntArray(
  char *zIntArray, 
  int nOut, 
  tRowcnt *aOut, 
  int *pbUnordered
){
  char *z = zIntArray;
  int c;
  int i;
  tRowcnt v;

  assert( pbUnordered==0 || *pbUnordered==0 );

#ifdef SQLITE_ENABLE_STAT3_OR_STAT4
  if( z==0 ) z = "";
#else
  if( NEVER(z==0) ) z = "";
#endif
  for(i=0; *z && i<nOut; i++){
    v = 0;
    while( (c=z[0])>='0' && c<='9' ){
      v = v*10 + c - '0';
      z++;
    }
    aOut[i] = v;
    if( *z==' ' ) z++;
  }
  if( pbUnordered && strcmp(z, "unordered")==0 ){
    *pbUnordered = 1;
  }
}

/*
** This callback is invoked once for each index when reading the
** sqlite_stat1 table.  
**
**     argv[0] = name of the table
**     argv[1] = name of the index (might be NULL)
**     argv[2] = results of analysis - on integer for each column
**
** Entries for which argv[1]==NULL simply record the number of rows in
** the table.
*/
static int analysisLoader(void *pData, int argc, char **argv, char **NotUsed){
  analysisInfo *pInfo = (analysisInfo*)pData;
  Index *pIndex;
  Table *pTable;


  const char *z;

  assert( argc==3 );
  UNUSED_PARAMETER2(NotUsed, argc);

  if( argv==0 || argv[0]==0 || argv[2]==0 ){
    return 0;
  }
  pTable = sqlite3FindTable(pInfo->db, argv[0], pInfo->zDatabase);
  if( pTable==0 ){
    return 0;
  }
  if( argv[1] ){
    pIndex = sqlite3FindIndex(pInfo->db, argv[1], pInfo->zDatabase);
  }else{
    pIndex = 0;
  }

  z = argv[2];








  if( pIndex ){

    int bUnordered = 0;
    decodeIntArray((char*)z, pIndex->nColumn+1, pIndex->aiRowEst,&bUnordered);

    if( pIndex->pPartIdxWhere==0 ) pTable->nRowEst = pIndex->aiRowEst[0];
    pIndex->bUnordered = bUnordered;
  }else{
    decodeIntArray((char*)z, 1, &pTable->nRowEst, 0);
  }

  return 0;
}

/*
** If the Index.aSample variable is not NULL, delete the aSample[] array
** and its contents.
*/
SQLITE_PRIVATE void sqlite3DeleteIndexSamples(sqlite3 *db, Index *pIdx){
#ifdef SQLITE_ENABLE_STAT3_OR_STAT4
  if( pIdx->aSample ){
    int j;
    for(j=0; j<pIdx->nSample; j++){
      IndexSample *p = &pIdx->aSample[j];

      sqlite3DbFree(db, p->p);

    }
    sqlite3DbFree(db, pIdx->aSample);
  }
  if( db && db->pnBytesFreed==0 ){
    pIdx->nSample = 0;
    pIdx->aSample = 0;
  }
#else
  UNUSED_PARAMETER(db);
  UNUSED_PARAMETER(pIdx);
#endif /* SQLITE_ENABLE_STAT3_OR_STAT4 */
}

#ifdef SQLITE_ENABLE_STAT3_OR_STAT4
/*
** Populate the pIdx->aAvgEq[] array based on the samples currently
** stored in pIdx->aSample[]. 
*/
static void initAvgEq(Index *pIdx){
  if( pIdx ){
    IndexSample *aSample = pIdx->aSample;
    IndexSample *pFinal = &aSample[pIdx->nSample-1];
    int iCol;
    for(iCol=0; iCol<pIdx->nColumn; iCol++){
      int i;                    /* Used to iterate through samples */
      tRowcnt sumEq = 0;        /* Sum of the nEq values */
      int nSum = 0;             /* Number of terms contributing to sumEq */
      tRowcnt avgEq = 0;
      tRowcnt nDLt = pFinal->anDLt[iCol];

      /* Set nSum to the number of distinct (iCol+1) field prefixes that
      ** occur in the stat4 table for this index before pFinal. Set
      ** sumEq to the sum of the nEq values for column iCol for the same
      ** set (adding the value only once where there exist dupicate 
      ** prefixes).  */
      for(i=0; i<(pIdx->nSample-1); i++){
        if( aSample[i].anDLt[iCol]!=aSample[i+1].anDLt[iCol] ){
          sumEq += aSample[i].anEq[iCol];
          nSum++;
        }
      }
      if( nDLt>nSum ){
        avgEq = (pFinal->anLt[iCol] - sumEq)/(nDLt - nSum);
      }
      if( avgEq==0 ) avgEq = 1;
      pIdx->aAvgEq[iCol] = avgEq;
      if( pIdx->nSampleCol==1 ) break;
    }
  }
}

/*
** Load the content from either the sqlite_stat4 or sqlite_stat3 table 
** into the relevant Index.aSample[] arrays.
**
** Arguments zSql1 and zSql2 must point to SQL statements that return
** data equivalent to the following (statements are different for stat3,
** see the caller of this function for details):
**
**    zSql1: SELECT idx,count(*) FROM %Q.sqlite_stat4 GROUP BY idx
**    zSql2: SELECT idx,neq,nlt,ndlt,sample FROM %Q.sqlite_stat4
**
** where %Q is replaced with the database name before the SQL is executed.
*/
static int loadStatTbl(
  sqlite3 *db,                  /* Database handle */
  int bStat3,                   /* Assume single column records only */
  const char *zSql1,            /* SQL statement 1 (see above) */
  const char *zSql2,            /* SQL statement 2 (see above) */
  const char *zDb               /* Database name (e.g. "main") */
){
  int rc;                       /* Result codes from subroutines */
  sqlite3_stmt *pStmt = 0;      /* An SQL statement being run */
  char *zSql;                   /* Text of the SQL statement */
  Index *pPrevIdx = 0;          /* Previous index in the loop */


  IndexSample *pSample;         /* A slot in pIdx->aSample[] */

  assert( db->lookaside.bEnabled==0 );




  zSql = sqlite3MPrintf(db, zSql1, zDb);


  if( !zSql ){
    return SQLITE_NOMEM;
  }
  rc = sqlite3_prepare(db, zSql, -1, &pStmt, 0);
  sqlite3DbFree(db, zSql);
  if( rc ) return rc;

  while( sqlite3_step(pStmt)==SQLITE_ROW ){
    int nIdxCol = 1;              /* Number of columns in stat4 records */
    int nAvgCol = 1;              /* Number of entries in Index.aAvgEq */

    char *zIndex;   /* Index name */
    Index *pIdx;    /* Pointer to the index object */
    int nSample;    /* Number of samples */
    int nByte;      /* Bytes of space required */
    int i;          /* Bytes of space required */
    tRowcnt *pSpace;

    zIndex = (char *)sqlite3_column_text(pStmt, 0);
    if( zIndex==0 ) continue;
    nSample = sqlite3_column_int(pStmt, 1);
    pIdx = sqlite3FindIndex(db, zIndex, zDb);
    assert( pIdx==0 || bStat3 || pIdx->nSample==0 );
    /* Index.nSample is non-zero at this point if data has already been
    ** loaded from the stat4 table. In this case ignore stat3 data.  */
    if( pIdx==0 || pIdx->nSample ) continue;
    if( bStat3==0 ){
      nIdxCol = pIdx->nColumn+1;
      nAvgCol = pIdx->nColumn;
    }
    pIdx->nSampleCol = nIdxCol;
    nByte = sizeof(IndexSample) * nSample;
    nByte += sizeof(tRowcnt) * nIdxCol * 3 * nSample;
    nByte += nAvgCol * sizeof(tRowcnt);     /* Space for Index.aAvgEq[] */

    pIdx->aSample = sqlite3DbMallocZero(db, nByte);

    if( pIdx->aSample==0 ){

      sqlite3_finalize(pStmt);
      return SQLITE_NOMEM;
    }
    pSpace = (tRowcnt*)&pIdx->aSample[nSample];
    pIdx->aAvgEq = pSpace; pSpace += nAvgCol;
    for(i=0; i<nSample; i++){
      pIdx->aSample[i].anEq = pSpace; pSpace += nIdxCol;
      pIdx->aSample[i].anLt = pSpace; pSpace += nIdxCol;
      pIdx->aSample[i].anDLt = pSpace; pSpace += nIdxCol;
    }
    assert( ((u8*)pSpace)-nByte==(u8*)(pIdx->aSample) );
  }
  rc = sqlite3_finalize(pStmt);
  if( rc ) return rc;

  zSql = sqlite3MPrintf(db, zSql2, zDb);

  if( !zSql ){
    return SQLITE_NOMEM;
  }
  rc = sqlite3_prepare(db, zSql, -1, &pStmt, 0);
  sqlite3DbFree(db, zSql);
  if( rc ) return rc;

  while( sqlite3_step(pStmt)==SQLITE_ROW ){
    char *zIndex;                 /* Index name */
    Index *pIdx;                  /* Pointer to the index object */
    int nCol = 1;                 /* Number of columns in index */


    zIndex = (char *)sqlite3_column_text(pStmt, 0);
    if( zIndex==0 ) continue;
    pIdx = sqlite3FindIndex(db, zIndex, zDb);
    if( pIdx==0 ) continue;
    /* This next condition is true if data has already been loaded from 
    ** the sqlite_stat4 table. In this case ignore stat3 data.  */
    nCol = pIdx->nSampleCol;
    if( bStat3 && nCol>1 ) continue;
    if( pIdx!=pPrevIdx ){
      initAvgEq(pPrevIdx);

      pPrevIdx = pIdx;

    }

    pSample = &pIdx->aSample[pIdx->nSample];
    decodeIntArray((char*)sqlite3_column_text(pStmt,1), nCol, pSample->anEq, 0);
    decodeIntArray((char*)sqlite3_column_text(pStmt,2), nCol, pSample->anLt, 0);
    decodeIntArray((char*)sqlite3_column_text(pStmt,3), nCol, pSample->anDLt,0);

    /* Take a copy of the sample. Add two 0x00 bytes the end of the buffer.
    ** This is in case the sample record is corrupted. In that case, the
    ** sqlite3VdbeRecordCompare() may read up to two varints past the
    ** end of the allocated buffer before it realizes it is dealing with
    ** a corrupt record. Adding the two 0x00 bytes prevents this from causing
    ** a buffer overread.  */
    pSample->n = sqlite3_column_bytes(pStmt, 4);
    pSample->p = sqlite3DbMallocZero(db, pSample->n + 2);
    if( pSample->p==0 ){


      sqlite3_finalize(pStmt);
      return SQLITE_NOMEM;
    }


    memcpy(pSample->p, sqlite3_column_blob(pStmt, 4), pSample->n);
    pIdx->nSample++;




  }

  rc = sqlite3_finalize(pStmt);
  if( rc==SQLITE_OK ) initAvgEq(pPrevIdx);
  return rc;
}



/*
** Load content from the sqlite_stat4 and sqlite_stat3 tables into 
** the Index.aSample[] arrays of all indices.
*/
static int loadStat4(sqlite3 *db, const char *zDb){
  int rc = SQLITE_OK;             /* Result codes from subroutines */

  assert( db->lookaside.bEnabled==0 );
  if( sqlite3FindTable(db, "sqlite_stat4", zDb) ){
    rc = loadStatTbl(db, 0,
      "SELECT idx,count(*) FROM %Q.sqlite_stat4 GROUP BY idx", 
      "SELECT idx,neq,nlt,ndlt,sample FROM %Q.sqlite_stat4",
      zDb
    );










  }


  if( rc==SQLITE_OK && sqlite3FindTable(db, "sqlite_stat3", zDb) ){
    rc = loadStatTbl(db, 1,
      "SELECT idx,count(*) FROM %Q.sqlite_stat3 GROUP BY idx", 
      "SELECT idx,neq,nlt,ndlt,sqlite_record(sample) FROM %Q.sqlite_stat3",
      zDb
    );
  }


  return rc;
}
#endif /* SQLITE_ENABLE_STAT3_OR_STAT4 */

/*
** Load the content of the sqlite_stat1 and sqlite_stat3/4 tables. The
** contents of sqlite_stat1 are used to populate the Index.aiRowEst[]
** arrays. The contents of sqlite_stat3/4 are used to populate the
** Index.aSample[] arrays.
**
** If the sqlite_stat1 table is not present in the database, SQLITE_ERROR
** is returned. In this case, even if SQLITE_ENABLE_STAT3/4 was defined 
** during compilation and the sqlite_stat3/4 table is present, no data is 
** read from it.
**
** If SQLITE_ENABLE_STAT3/4 was defined during compilation and the 
** sqlite_stat4 table is not present in the database, SQLITE_ERROR is
** returned. However, in this case, data is read from the sqlite_stat1
** table (if it is present) before returning.
**
** If an OOM error occurs, this function always sets db->mallocFailed.
** This means if the caller does not care about other errors, the return
** code may be ignored.
*/

  assert( db->aDb[iDb].pBt!=0 );

  /* Clear any prior statistics */
  assert( sqlite3SchemaMutexHeld(db, iDb, 0) );
  for(i=sqliteHashFirst(&db->aDb[iDb].pSchema->idxHash);i;i=sqliteHashNext(i)){
    Index *pIdx = sqliteHashData(i);
    sqlite3DefaultRowEst(pIdx);
#ifdef SQLITE_ENABLE_STAT3_OR_STAT4
    sqlite3DeleteIndexSamples(db, pIdx);
    pIdx->aSample = 0;
#endif
  }

  /* Check to make sure the sqlite_stat1 table exists */
  sInfo.db = db;

    rc = SQLITE_NOMEM;
  }else{
    rc = sqlite3_exec(db, zSql, analysisLoader, &sInfo, 0);
    sqlite3DbFree(db, zSql);
  }


  /* Load the statistics from the sqlite_stat4 table. */
#ifdef SQLITE_ENABLE_STAT3_OR_STAT4
  if( rc==SQLITE_OK ){
    int lookasideEnabled = db->lookaside.bEnabled;
    db->lookaside.bEnabled = 0;
    rc = loadStat4(db, sInfo.zDatabase);
    db->lookaside.bEnabled = lookasideEnabled;
  }
#endif

  if( rc==SQLITE_NOMEM ){
    db->mallocFailed = 1;
  }

        "attached databases must use the same text encoding as main database");
      rc = SQLITE_ERROR;
    }
    pPager = sqlite3BtreePager(aNew->pBt);
    sqlite3PagerLockingMode(pPager, db->dfltLockMode);
    sqlite3BtreeSecureDelete(aNew->pBt,
                             sqlite3BtreeSecureDelete(db->aDb[0].pBt,-1) );
#ifndef SQLITE_OMIT_PAGER_PRAGMAS
    sqlite3BtreeSetPagerFlags(aNew->pBt, 3 | (db->flags & PAGER_FLAGS_MASK));
#endif
  }
  aNew->safety_level = 3;
  aNew->zName = sqlite3DbStrDup(db, zName);
  if( rc==SQLITE_OK && aNew->zName==0 ){
    rc = SQLITE_NOMEM;
  }

  Parse *pParse,         /* The parsing context */
  int iDb,               /* The database number */
  const char *zType,     /* "idx" or "tbl" */
  const char *zName      /* Name of index or table */
){
  int i;
  const char *zDbName = pParse->db->aDb[iDb].zName;
  for(i=1; i<=4; i++){
    char zTab[24];
    sqlite3_snprintf(sizeof(zTab),zTab,"sqlite_stat%d",i);
    if( sqlite3FindTable(pParse->db, zTab, zDbName) ){
      sqlite3NestedParse(pParse,
        "DELETE FROM %Q.%s WHERE %s=%Q",
        zDbName, zTab, zType, zName
      );

  for(i=0; i<ArraySize(aBuiltinFunc); i++){
    sqlite3FuncDefInsert(pHash, &aFunc[i]);
  }
  sqlite3RegisterDateTimeFunctions();
#ifndef SQLITE_OMIT_ALTERTABLE
  sqlite3AlterFunctions();
#endif
#if defined(SQLITE_ENABLE_STAT3) || defined(SQLITE_ENABLE_STAT4)
  sqlite3AnalyzeFunctions();
#endif
}

/************** End of func.c ************************************************/
/************** Begin file fkey.c ********************************************/
/*
**

        sqlite3BtreeSetPagerFlags(pDb->pBt,
                 pDb->safety_level | (db->flags & PAGER_FLAGS_MASK) );
      }
      pDb++;
    }
  }
}
#else
# define setAllPagerFlags(X)  /* no-op */
#endif


#ifndef SQLITE_OMIT_FLAG_PRAGMAS
/*
** Check to see if zRight and zLeft refer to a pragma that queries
** or changes one of the flags in db->flags.  Return 1 if so and 0 if not.

  **
  ** Get or set the size limit on rollback journal files.
  */
  if( sqlite3StrICmp(zLeft,"journal_size_limit")==0 ){
    Pager *pPager = sqlite3BtreePager(pDb->pBt);
    i64 iLimit = -2;
    if( zRight ){
      sqlite3Atoi64(zRight, &iLimit, sqlite3Strlen30(zRight), SQLITE_UTF8);
      if( iLimit<-1 ) iLimit = -1;
    }
    iLimit = sqlite3PagerJournalSizeLimit(pPager, iLimit);
    returnSingleInt(pParse, "journal_size_limit", iLimit);
  }else

#endif /* SQLITE_OMIT_PAGER_PRAGMAS */

  **
  ** This value is advisory.  The underlying VFS is free to memory map
  ** as little or as much as it wants.  Except, if N is set to 0 then the
  ** upper layers will never invoke the xFetch interfaces to the VFS.
  */
  if( sqlite3StrICmp(zLeft,"mmap_size")==0 ){
    sqlite3_int64 sz;
#if SQLITE_MAX_MMAP_SIZE>0
    assert( sqlite3SchemaMutexHeld(db, iDb, 0) );
    if( zRight ){
      int ii;
      sqlite3Atoi64(zRight, &sz, sqlite3Strlen30(zRight), SQLITE_UTF8);
      if( sz<0 ) sz = sqlite3GlobalConfig.szMmap;
      if( pId2->n==0 ) db->szMmap = sz;
      for(ii=db->nDb-1; ii>=0; ii--){
        if( db->aDb[ii].pBt && (ii==iDb || pId2->n==0) ){
          sqlite3BtreeSetMmapLimit(db->aDb[ii].pBt, sz);
        }
      }
    }
    sz = -1;
    rc = sqlite3_file_control(db, zDb, SQLITE_FCNTL_MMAP_SIZE, &sz);
#else
    sz = 0;
    rc = SQLITE_OK;
#endif
    if( rc==SQLITE_OK ){
      returnSingleInt(pParse, "mmap_size", sz);
    }else if( rc!=SQLITE_NOTFOUND ){
      pParse->nErr++;
      pParse->rc = rc;
    }

** on register iReg. This is used when an equivalent integer value is 
** stored in place of an 8-byte floating point value in order to save 
** space.
*/
SQLITE_PRIVATE void sqlite3ColumnDefault(Vdbe *v, Table *pTab, int i, int iReg){
  assert( pTab!=0 );
  if( !pTab->pSelect ){
    sqlite3_value *pValue = 0;
    u8 enc = ENC(sqlite3VdbeDb(v));
    Column *pCol = &pTab->aCol[i];
    VdbeComment((v, "%s.%s", pTab->zName, pCol->zName));
    assert( i<pTab->nCol );
    sqlite3ValueFromExpr(sqlite3VdbeDb(v), pCol->pDflt, enc, 
                         pCol->affinity, &pValue);
    if( pValue ){

#define TERM_DYNAMIC    0x01   /* Need to call sqlite3ExprDelete(db, pExpr) */
#define TERM_VIRTUAL    0x02   /* Added by the optimizer.  Do not code */
#define TERM_CODED      0x04   /* This term is already coded */
#define TERM_COPIED     0x08   /* Has a child */
#define TERM_ORINFO     0x10   /* Need to free the WhereTerm.u.pOrInfo object */
#define TERM_ANDINFO    0x20   /* Need to free the WhereTerm.u.pAndInfo obj */
#define TERM_OR_OK      0x40   /* Used during OR-clause processing */
#ifdef SQLITE_ENABLE_STAT3_OR_STAT4
#  define TERM_VNULL    0x80   /* Manufactured x>NULL or x<=NULL term */
#else
#  define TERM_VNULL    0x00   /* Disabled if not using stat3 */
#endif

/*
** An instance of the WhereScan object is used as an iterator for locating

*/
struct WhereLoopBuilder {
  WhereInfo *pWInfo;        /* Information about this WHERE */
  WhereClause *pWC;         /* WHERE clause terms */
  ExprList *pOrderBy;       /* ORDER BY clause */
  WhereLoop *pNew;          /* Template WhereLoop */
  WhereOrSet *pOrSet;       /* Record best loops here, if not NULL */
#ifdef SQLITE_ENABLE_STAT3_OR_STAT4
  UnpackedRecord *pRec;     /* Probe for stat4 (if required) */
  int nRecValid;            /* Number of valid fields currently in pRec */
#endif
};

/*
** The WHERE clause processing routine has two halves.  The
** first part does the start of the WHERE loop and the second
** half does the tail of the WHERE loop.  An instance of
** this structure is returned by the first half and passed

#endif /* SQLITE_OMIT_VIRTUALTABLE */

/*
** If the pBase expression originated in the ON or USING clause of
** a join, then transfer the appropriate markings over to derived.
*/
static void transferJoinMarkings(Expr *pDerived, Expr *pBase){
  if( pDerived ){
    pDerived->flags |= pBase->flags & EP_FromJoin;
    pDerived->iRightJoinTable = pBase->iRightJoinTable;
  }
}

#if !defined(SQLITE_OMIT_OR_OPTIMIZATION) && !defined(SQLITE_OMIT_SUBQUERY)
/*
** Analyze a term that consists of two or more OR-connected
** subterms.  So in:
**

    assert( pList->nExpr==2 );
    for(i=0; i<2; i++){
      Expr *pNewExpr;
      int idxNew;
      pNewExpr = sqlite3PExpr(pParse, ops[i], 
                             sqlite3ExprDup(db, pExpr->pLeft, 0),
                             sqlite3ExprDup(db, pList->a[i].pExpr, 0), 0);
      transferJoinMarkings(pNewExpr, pExpr);
      idxNew = whereClauseInsert(pWC, pNewExpr, TERM_VIRTUAL|TERM_DYNAMIC);
      testcase( idxNew==0 );
      exprAnalyze(pSrc, pWC, idxNew);
      pTerm = &pWC->a[idxTerm];
      pWC->a[idxNew].iParent = idxTerm;
    }
    pTerm->nChild = 2;

    }
    sCollSeqName.z = noCase ? "NOCASE" : "BINARY";
    sCollSeqName.n = 6;
    pNewExpr1 = sqlite3ExprDup(db, pLeft, 0);
    pNewExpr1 = sqlite3PExpr(pParse, TK_GE, 
           sqlite3ExprAddCollateToken(pParse,pNewExpr1,&sCollSeqName),
           pStr1, 0);
    transferJoinMarkings(pNewExpr1, pExpr);
    idxNew1 = whereClauseInsert(pWC, pNewExpr1, TERM_VIRTUAL|TERM_DYNAMIC);
    testcase( idxNew1==0 );
    exprAnalyze(pSrc, pWC, idxNew1);
    pNewExpr2 = sqlite3ExprDup(db, pLeft, 0);
    pNewExpr2 = sqlite3PExpr(pParse, TK_LT,
           sqlite3ExprAddCollateToken(pParse,pNewExpr2,&sCollSeqName),
           pStr2, 0);
    transferJoinMarkings(pNewExpr2, pExpr);
    idxNew2 = whereClauseInsert(pWC, pNewExpr2, TERM_VIRTUAL|TERM_DYNAMIC);
    testcase( idxNew2==0 );
    exprAnalyze(pSrc, pWC, idxNew2);
    pTerm = &pWC->a[idxTerm];
    if( isComplete ){
      pWC->a[idxNew1].iParent = idxTerm;
      pWC->a[idxNew2].iParent = idxTerm;

      pTerm->nChild = 1;
      pTerm->wtFlags |= TERM_COPIED;
      pNewTerm->prereqAll = pTerm->prereqAll;
    }
  }
#endif /* SQLITE_OMIT_VIRTUALTABLE */

#ifdef SQLITE_ENABLE_STAT3_OR_STAT4
  /* When sqlite_stat3 histogram data is available an operator of the
  ** form "x IS NOT NULL" can sometimes be evaluated more efficiently
  ** as "x>NULL" if x is not an INTEGER PRIMARY KEY.  So construct a
  ** virtual term of that form.
  **
  ** Note that the virtual term must be tagged with TERM_VNULL.  This
  ** TERM_VNULL tag will suppress the not-null check at the beginning

      pNewTerm->iParent = idxTerm;
      pTerm = &pWC->a[idxTerm];
      pTerm->nChild = 1;
      pTerm->wtFlags |= TERM_COPIED;
      pNewTerm->prereqAll = pTerm->prereqAll;
    }
  }
#endif /* SQLITE_ENABLE_STAT3_OR_STAT4 */

  /* Prevent ON clause terms of a LEFT JOIN from being used to drive
  ** an index for tables to the left of the join.
  */
  pTerm->prereqRight |= extraRight;
}

  }

  return pParse->nErr;
}
#endif /* !defined(SQLITE_OMIT_VIRTUALTABLE) */


#ifdef SQLITE_ENABLE_STAT3_OR_STAT4
/*
** Estimate the location of a particular key among all keys in an
** index.  Store the results in aStat as follows:
**
**    aStat[0]      Est. number of rows less than pVal
**    aStat[1]      Est. number of rows equal to pVal
**
** Return SQLITE_OK on success.
*/
static void whereKeyStats(
  Parse *pParse,              /* Database connection */
  Index *pIdx,                /* Index to consider domain of */
  UnpackedRecord *pRec,       /* Vector of values to consider */
  int roundUp,                /* Round up if true.  Round down if false */
  tRowcnt *aStat              /* OUT: stats written here */
){

  IndexSample *aSample = pIdx->aSample;
  int iCol = pRec->nField-1;  /* Index of required stats in anEq[] etc. */
  int iMin = 0;               /* Smallest sample not yet tested */
  int i = pIdx->nSample;      /* Smallest sample larger than or equal to pRec */
  int iTest;                  /* Next sample to test */
  int res;                    /* Result of comparison operation */


  assert( pIdx->nSample>0 );


  assert( pRec->nField>0 && iCol<pIdx->nSampleCol );

  do{


    iTest = (iMin+i)/2;

    res = sqlite3VdbeRecordCompare(aSample[iTest].n, aSample[iTest].p, pRec);


    if( res<0 ){
      iMin = iTest+1;


    }else{


      i = iTest;

    }
  }while( res && iMin<i );


#ifdef SQLITE_DEBUG






  /* The following assert statements check that the binary search code
  ** above found the right answer. This block serves no purpose other
  ** than to invoke the asserts.  */


  if( res==0 ){









    /* If (res==0) is true, then sample $i must be equal to pRec */




    assert( i<pIdx->nSample );
    assert( 0==sqlite3VdbeRecordCompare(aSample[i].n, aSample[i].p, pRec)
         || pParse->db->mallocFailed );






  }else{












    /* Otherwise, pRec must be smaller than sample $i and larger than
    ** sample ($i-1).  */






    assert( i==pIdx->nSample 

         || sqlite3VdbeRecordCompare(aSample[i].n, aSample[i].p, pRec)>0
         || pParse->db->mallocFailed );
    assert( i==0
         || sqlite3VdbeRecordCompare(aSample[i-1].n, aSample[i-1].p, pRec)<0
         || pParse->db->mallocFailed );

  }



#endif /* ifdef SQLITE_DEBUG */











  /* At this point, aSample[i] is the first sample that is greater than
  ** or equal to pVal.  Or if i==pIdx->nSample, then all samples are less
  ** than pVal.  If aSample[i]==pVal, then res==0.
  */
  if( res==0 ){

    aStat[0] = aSample[i].anLt[iCol];
    aStat[1] = aSample[i].anEq[iCol];
  }else{
    tRowcnt iLower, iUpper, iGap;
    if( i==0 ){
      iLower = 0;
      iUpper = aSample[0].anLt[iCol];
    }else{
      iUpper = i>=pIdx->nSample ? pIdx->aiRowEst[0] : aSample[i].anLt[iCol];
      iLower = aSample[i-1].anEq[iCol] + aSample[i-1].anLt[iCol];
    }
    aStat[1] = (pIdx->nColumn>iCol ? pIdx->aAvgEq[iCol] : 1);
    if( iLower>=iUpper ){
      iGap = 0;
    }else{
      iGap = iUpper - iLower;
    }
    if( roundUp ){
      iGap = (iGap*2)/3;
    }else{
      iGap = iGap/3;
    }
    aStat[0] = iLower + iGap;
  }

}
#endif /* SQLITE_ENABLE_STAT3_OR_STAT4 */




































/*
** This function is used to estimate the number of rows that will be visited
** by scanning an index for a range of values. The range may have an upper
** bound, a lower bound, or both. The WHERE clause terms that set the upper
** and lower bounds are represented by pLower and pUpper respectively. For
** example, assuming that index p is on t1(a):
**
**   ... FROM t1 WHERE a > ? AND a < ? ...
**                    |_____|   |_____|
**                       |         |
**                     pLower    pUpper
**
** If either of the upper or lower bound is not present, then NULL is passed in
** place of the corresponding WhereTerm.
**
** The value in (pBuilder->pNew->u.btree.nEq) is the index of the index
** column subject to the range constraint. Or, equivalently, the number of
** equality constraints optimized by the proposed index scan. For example,
** assuming index p is on t1(a, b), and the SQL query is:
**
**   ... FROM t1 WHERE a = ? AND b > ? AND b < ? ...
**
** then nEq is set to 1 (as the range restricted column, b, is the second 
** left-most column of the index). Or, if the query is:
**
**   ... FROM t1 WHERE a > ? AND a < ? ...
**
** then nEq is set to 0.
**
** When this function is called, *pnOut is set to the whereCost() of the
** number of rows that the index scan is expected to visit without 
** considering the range constraints. If nEq is 0, this is the number of 
** rows in the index. Assuming no error occurs, *pnOut is adjusted (reduced)
** to account for the range contraints pLower and pUpper.
** 
** In the absence of sqlite_stat4 ANALYZE data, or if such data cannot be
** used, each range inequality reduces the search space by a factor of 4. 
** Hence a pair of constraints (x>? AND x<?) reduces the expected number of
** rows visited by a factor of 16.
*/
static int whereRangeScanEst(
  Parse *pParse,       /* Parsing & code generating context */

  WhereLoopBuilder *pBuilder,
  WhereTerm *pLower,   /* Lower bound on the range. ex: "x>123" Might be NULL */
  WhereTerm *pUpper,   /* Upper bound on the range. ex: "x<455" Might be NULL */
  WhereCost *pnOut     /* IN/OUT: Number of rows visited */
){
  int rc = SQLITE_OK;
  int nOut = (int)*pnOut;

#ifdef SQLITE_ENABLE_STAT3_OR_STAT4
  Index *p = pBuilder->pNew->u.btree.pIndex;
  int nEq = pBuilder->pNew->u.btree.nEq;

  if( nEq==pBuilder->nRecValid
   && nEq<p->nSampleCol
   && p->nSample 
   && OptimizationEnabled(pParse->db, SQLITE_Stat3) 
  ){
    UnpackedRecord *pRec = pBuilder->pRec;
    tRowcnt a[2];
    u8 aff = p->pTable->aCol[p->aiColumn[0]].affinity;

    /* Variable iLower will be set to the estimate of the number of rows in 
    ** the index that are less than the lower bound of the range query. The
    ** lower bound being the concatenation of $P and $L, where $P is the
    ** key-prefix formed by the nEq values matched against the nEq left-most
    ** columns of the index, and $L is the value in pLower.
    **
    ** Or, if pLower is NULL or $L cannot be extracted from it (because it
    ** is not a simple variable or literal value), the lower bound of the
    ** range is $P. Due to a quirk in the way whereKeyStats() works, even
    ** if $L is available, whereKeyStats() is called for both ($P) and 
    ** ($P:$L) and the larger of the two returned values used.
    **
    ** Similarly, iUpper is to be set to the estimate of the number of rows
    ** less than the upper bound of the range query. Where the upper bound
    ** is either ($P) or ($P:$U). Again, even if $U is available, both values
    ** of iUpper are requested of whereKeyStats() and the smaller used.
    */
    tRowcnt iLower;
    tRowcnt iUpper;

    /* Determine iLower and iUpper using ($P) only. */
    if( nEq==0 ){
      iLower = 0;
      iUpper = p->aiRowEst[0];
    }else{
      /* Note: this call could be optimized away - since the same values must 
      ** have been requested when testing key $P in whereEqualScanEst().  */
      whereKeyStats(pParse, p, pRec, 0, a);
      iLower = a[0];
      iUpper = a[0] + a[1];
    }

    /* If possible, improve on the iLower estimate using ($P:$L). */
    if( pLower ){
      int bOk;                    /* True if value is extracted from pExpr */
      Expr *pExpr = pLower->pExpr->pRight;

      assert( (pLower->eOperator & (WO_GT|WO_GE))!=0 );
      rc = sqlite3Stat4ProbeSetValue(pParse, p, &pRec, pExpr, aff, nEq, &bOk);
      if( rc==SQLITE_OK && bOk ){
        tRowcnt iNew;
        whereKeyStats(pParse, p, pRec, 0, a);


        iNew = a[0] + ((pLower->eOperator & WO_GT) ? a[1] : 0);
        if( iNew>iLower ) iLower = iNew;
      }

    }

    /* If possible, improve on the iUpper estimate using ($P:$U). */
    if( pUpper ){
      int bOk;                    /* True if value is extracted from pExpr */
      Expr *pExpr = pUpper->pExpr->pRight;

      assert( (pUpper->eOperator & (WO_LT|WO_LE))!=0 );
      rc = sqlite3Stat4ProbeSetValue(pParse, p, &pRec, pExpr, aff, nEq, &bOk);
      if( rc==SQLITE_OK && bOk ){
        tRowcnt iNew;
        whereKeyStats(pParse, p, pRec, 1, a);


        iNew = a[0] + ((pUpper->eOperator & WO_LE) ? a[1] : 0);
        if( iNew<iUpper ) iUpper = iNew;
      }

    }

    pBuilder->pRec = pRec;
    if( rc==SQLITE_OK ){
      WhereCost nNew;
      if( iUpper>iLower ){
        nNew = whereCost(iUpper - iLower);
      }else{
        nNew = 10;        assert( 10==whereCost(2) );
      }
      if( nNew<nOut ){
        nOut = nNew;
      }
      *pnOut = (WhereCost)nOut;
      WHERETRACE(0x100, ("range scan regions: %u..%u  est=%d\n",
                         (u32)iLower, (u32)iUpper, nOut));
      return SQLITE_OK;
    }
  }
#else
  UNUSED_PARAMETER(pParse);

  UNUSED_PARAMETER(pBuilder);
#endif
  assert( pLower || pUpper );

  /* TUNING:  Each inequality constraint reduces the search space 4-fold.
  ** A BETWEEN operator, therefore, reduces the search space 16-fold */
  if( pLower && (pLower->wtFlags & TERM_VNULL)==0 ){
    nOut -= 20;        assert( 20==whereCost(4) );
  }
  if( pUpper ){
    nOut -= 20;        assert( 20==whereCost(4) );
  }
  if( nOut<10 ) nOut = 10;
  *pnOut = (WhereCost)nOut;
  return rc;
}

#ifdef SQLITE_ENABLE_STAT3_OR_STAT4
/*
** Estimate the number of rows that will be returned based on
** an equality constraint x=VALUE and where that VALUE occurs in
** the histogram data.  This only works when x is the left-most
** column of an index and sqlite_stat3 histogram data is available
** for that index.  When pExpr==NULL that means the constraint is
** "x IS NULL" instead of "x=VALUE".
**
** Write the estimated row count into *pnRow and return SQLITE_OK. 
** If unable to make an estimate, leave *pnRow unchanged and return
** non-zero.
**
** This routine can fail if it is unable to load a collating sequence
** required for string comparison, or if unable to allocate memory
** for a UTF conversion required for comparison.  The error is stored
** in the pParse structure.
*/
static int whereEqualScanEst(
  Parse *pParse,       /* Parsing & code generating context */
  WhereLoopBuilder *pBuilder,
  Expr *pExpr,         /* Expression for VALUE in the x=VALUE constraint */
  tRowcnt *pnRow       /* Write the revised row estimate here */
){
  Index *p = pBuilder->pNew->u.btree.pIndex;
  int nEq = pBuilder->pNew->u.btree.nEq;
  UnpackedRecord *pRec = pBuilder->pRec;
  u8 aff;                   /* Column affinity */
  int rc;                   /* Subfunction return code */
  tRowcnt a[2];             /* Statistics */
  int bOk;

  assert( nEq>=1 );
  assert( nEq<=(p->nColumn+1) );
  assert( p->aSample!=0 );
  assert( p->nSample>0 );
  assert( pBuilder->nRecValid<nEq );

  /* If values are not available for all fields of the index to the left
  ** of this one, no estimate can be made. Return SQLITE_NOTFOUND. */
  if( pBuilder->nRecValid<(nEq-1) ){
    return SQLITE_NOTFOUND;
  }

  /* This is an optimization only. The call to sqlite3Stat4ProbeSetValue()
  ** below would return the same value.  */
  if( nEq>p->nColumn ){

    *pnRow = 1;
    return SQLITE_OK;
  }

  aff = p->pTable->aCol[p->aiColumn[nEq-1]].affinity;
  rc = sqlite3Stat4ProbeSetValue(pParse, p, &pRec, pExpr, aff, nEq-1, &bOk);
  pBuilder->pRec = pRec;
  if( rc!=SQLITE_OK ) return rc;
  if( bOk==0 ) return SQLITE_NOTFOUND;
  pBuilder->nRecValid = nEq;

  whereKeyStats(pParse, p, pRec, 0, a);

  WHERETRACE(0x100,("equality scan regions: %d\n", (int)a[1]));
  *pnRow = a[1];
  


  return rc;
}
#endif /* SQLITE_ENABLE_STAT3_OR_STAT4 */

#ifdef SQLITE_ENABLE_STAT3_OR_STAT4
/*
** Estimate the number of rows that will be returned based on
** an IN constraint where the right-hand side of the IN operator
** is a list of values.  Example:
**
**        WHERE x IN (1,2,3,4)
**
** Write the estimated row count into *pnRow and return SQLITE_OK. 
** If unable to make an estimate, leave *pnRow unchanged and return
** non-zero.
**
** This routine can fail if it is unable to load a collating sequence
** required for string comparison, or if unable to allocate memory
** for a UTF conversion required for comparison.  The error is stored
** in the pParse structure.
*/
static int whereInScanEst(
  Parse *pParse,       /* Parsing & code generating context */
  WhereLoopBuilder *pBuilder,
  ExprList *pList,     /* The value list on the RHS of "x IN (v1,v2,v3,...)" */
  tRowcnt *pnRow       /* Write the revised row estimate here */
){
  Index *p = pBuilder->pNew->u.btree.pIndex;
  int nRecValid = pBuilder->nRecValid;
  int rc = SQLITE_OK;     /* Subfunction return code */
  tRowcnt nEst;           /* Number of rows for a single term */
  tRowcnt nRowEst = 0;    /* New estimate of the number of rows */
  int i;                  /* Loop counter */

  assert( p->aSample!=0 );
  for(i=0; rc==SQLITE_OK && i<pList->nExpr; i++){
    nEst = p->aiRowEst[0];
    rc = whereEqualScanEst(pParse, pBuilder, pList->a[i].pExpr, &nEst);
    nRowEst += nEst;
    pBuilder->nRecValid = nRecValid;
  }

  if( rc==SQLITE_OK ){
    if( nRowEst > p->aiRowEst[0] ) nRowEst = p->aiRowEst[0];
    *pnRow = nRowEst;
    WHERETRACE(0x100,("IN row estimate: est=%g\n", nRowEst));
  }
  assert( pBuilder->nRecValid==nRecValid );
  return rc;
}
#endif /* SQLITE_ENABLE_STAT3_OR_STAT4 */

/*
** Disable a term in the WHERE clause.  Except, do not disable the term
** if it controls a LEFT OUTER JOIN and it did not originate in the ON
** or USING clause of that join.
**
** Consider the term t2.z='ok' in the following queries:

  zAff = sqlite3DbStrDup(pParse->db, sqlite3IndexAffinityStr(v, pIdx));
  if( !zAff ){
    pParse->db->mallocFailed = 1;
  }

  /* Evaluate the equality constraints
  */
  assert( zAff==0 || (int)strlen(zAff)>=nEq );
  for(j=0; j<nEq; j++){
    int r1;
    pTerm = pLoop->aLTerm[j];
    assert( pTerm!=0 );
    /* The following true for indices with redundant columns. 
    ** Ex: CREATE INDEX i1 ON t1(a,b,a); SELECT * FROM t1 WHERE a=0 AND b=0; */
    testcase( (pTerm->wtFlags & TERM_CODED)!=0 );

  saved_wsFlags = pNew->wsFlags;
  saved_prereq = pNew->prereq;
  saved_nOut = pNew->nOut;
  pNew->rSetup = 0;
  rLogSize = estLog(whereCost(pProbe->aiRowEst[0]));
  for(; rc==SQLITE_OK && pTerm!=0; pTerm = whereScanNext(&scan)){
    int nIn = 0;
#ifdef SQLITE_ENABLE_STAT3_OR_STAT4
    int nRecValid = pBuilder->nRecValid;
    assert( pNew->nOut==saved_nOut );
    if( (pTerm->wtFlags & TERM_VNULL)!=0 && pSrc->pTab->aCol[iCol].notNull ){
      continue; /* skip IS NOT NULL constraints on a NOT NULL column */
    }
#endif
    if( pTerm->prereqRight & pNew->maskSelf ) continue;




    assert( pNew->nOut==saved_nOut );

    pNew->wsFlags = saved_wsFlags;
    pNew->u.btree.nEq = saved_nEq;
    pNew->nLTerm = saved_nLTerm;
    if( whereLoopResize(db, pNew, pNew->nLTerm+1) ) break; /* OOM */
    pNew->aLTerm[pNew->nLTerm++] = pTerm;
    pNew->prereq = (saved_prereq | pTerm->prereqRight) & ~pNew->maskSelf;
    pNew->rRun = rLogSize; /* Baseline cost is log2(N).  Adjustments below */

      pNew->wsFlags |= WHERE_COLUMN_RANGE|WHERE_TOP_LIMIT;
      pTop = pTerm;
      pBtm = (pNew->wsFlags & WHERE_BTM_LIMIT)!=0 ?
                     pNew->aLTerm[pNew->nLTerm-2] : 0;
    }
    if( pNew->wsFlags & WHERE_COLUMN_RANGE ){
      /* Adjust nOut and rRun for STAT3 range values */
      assert( pNew->nOut==saved_nOut );
      whereRangeScanEst(pParse, pBuilder, pBtm, pTop, &pNew->nOut);


    }
#ifdef SQLITE_ENABLE_STAT3_OR_STAT4
    if( nInMul==0 
     && pProbe->nSample 
     && pNew->u.btree.nEq<=pProbe->nSampleCol
     && OptimizationEnabled(db, SQLITE_Stat3) 
    ){
      Expr *pExpr = pTerm->pExpr;
      tRowcnt nOut = 0;
      if( (pTerm->eOperator & (WO_EQ|WO_ISNULL))!=0 ){
        testcase( pTerm->eOperator & WO_EQ );
        testcase( pTerm->eOperator & WO_ISNULL );
        rc = whereEqualScanEst(pParse, pBuilder, pExpr->pRight, &nOut);
      }else if( (pTerm->eOperator & WO_IN)
             &&  !ExprHasProperty(pExpr, EP_xIsSelect)  ){
        rc = whereInScanEst(pParse, pBuilder, pExpr->x.pList, &nOut);
      }
      assert( nOut==0 || rc==SQLITE_OK );
      if( nOut ){
        nOut = whereCost(nOut);
        pNew->nOut = MIN(nOut, saved_nOut);
      }
    }
#endif
    if( (pNew->wsFlags & (WHERE_IDX_ONLY|WHERE_IPK))==0 ){
      /* Each row involves a step of the index, then a binary search of
      ** the main table */
      pNew->rRun =  whereCostAdd(pNew->rRun, rLogSize>27 ? rLogSize-17 : 10);
    }
    /* Step cost for each output row */
    pNew->rRun = whereCostAdd(pNew->rRun, pNew->nOut);
    /* TBD: Adjust nOut for additional constraints */
    rc = whereLoopInsert(pBuilder, pNew);
    if( (pNew->wsFlags & WHERE_TOP_LIMIT)==0
     && pNew->u.btree.nEq<(pProbe->nColumn + (pProbe->zName!=0))
    ){
      whereLoopAddBtreeIndex(pBuilder, pSrc, pProbe, nInMul+nIn);
    }
    pNew->nOut = saved_nOut;
#ifdef SQLITE_ENABLE_STAT3_OR_STAT4
    pBuilder->nRecValid = nRecValid;
#endif
  }
  pNew->prereq = saved_prereq;
  pNew->u.btree.nEq = saved_nEq;
  pNew->wsFlags = saved_wsFlags;
  pNew->nOut = saved_nOut;
  pNew->nLTerm = saved_nLTerm;
  return rc;

      sPk.pNext = pFirst;
    }
    pProbe = &sPk;
  }
  rSize = whereCost(pSrc->pTab->nRowEst);
  rLogSize = estLog(rSize);

#ifndef SQLITE_OMIT_AUTOMATIC_INDEX
  /* Automatic indexes */
  if( !pBuilder->pOrSet
   && (pWInfo->pParse->db->flags & SQLITE_AutoIndex)!=0
   && pSrc->pIndex==0
   && !pSrc->viaCoroutine
   && !pSrc->notIndexed
   && !pSrc->isCorrelated

        pNew->rRun = whereCostAdd(rLogSize,pNew->nOut);
        pNew->wsFlags = WHERE_AUTO_INDEX;
        pNew->prereq = mExtra | pTerm->prereqRight;
        rc = whereLoopInsert(pBuilder, pNew);
      }
    }
  }
#endif /* SQLITE_OMIT_AUTOMATIC_INDEX */

  /* Loop over all indices
  */
  for(; rc==SQLITE_OK && pProbe; pProbe=pProbe->pNext, iSortIdx++){
    if( pProbe->pPartIdxWhere!=0
     && !whereUsablePartialIndex(pNew->iTab, pWC, pProbe->pPartIdxWhere) ){
      continue;  /* Partial index inappropriate for this query */

          ** which we will simplify to just N*log2(N) */
          pNew->rRun = rSize + rLogSize;
        }
        rc = whereLoopInsert(pBuilder, pNew);
        if( rc ) break;
      }
    }

    rc = whereLoopAddBtreeIndex(pBuilder, pSrc, pProbe, 0);
#ifdef SQLITE_ENABLE_STAT3_OR_STAT4
    sqlite3Stat4ProbeFree(pBuilder->pRec);
    pBuilder->nRecValid = 0;
    pBuilder->pRec = 0;
#endif

    /* If there was an INDEXED BY clause, then only that one index is
    ** considered. */
    if( pSrc->pIndex ) break;
  }
  return rc;
}

** string contains the date and time of the check-in (UTC) and an SHA1
** hash of the entire source tree.
**
** See also: [sqlite3_libversion()],
** [sqlite3_libversion_number()], [sqlite3_sourceid()],
** [sqlite_version()] and [sqlite_source_id()].
*/
#define SQLITE_VERSION        "3.8.1"
#define SQLITE_VERSION_NUMBER 3008001
#define SQLITE_SOURCE_ID      "2013-08-29 01:09:14 9229aeb361f9805894321327d05aba855b8799f3"

/*
** CAPI3REF: Run-Time Library Version Numbers
** KEYWORDS: sqlite3_version, sqlite3_sourceid
**
** These interfaces provide the same information as the [SQLITE_VERSION],
** [SQLITE_VERSION_NUMBER], and [SQLITE_SOURCE_ID] C preprocessor macros

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ADO.NET SQLite Data Provider<br />
Version 1.0.89.0 September XX, 2013 <font color="red">(release scheduled)</font><br />
Using <a href="http://www.sqlite.org/src/info/trunk">SQLite 3.8.1</a><br />
Originally written by Robert Simpson<br />
Released to the public domain, use at your own risk!<br />
Official provider website:&nbsp;<a href="http://system.data.sqlite.org/">http://system.data.sqlite.org/</a><br />
Legacy versions:&nbsp;<a href="http://sqlite.phxsoftware.com/">http://sqlite.phxsoftware.com/</a><br />
<br />
The current development version can be downloaded from <a href="http://system.data.sqlite.org/index.html/timeline?y=ci">
http://system.data.sqlite.org/index.html/timeline?y=ci</a>

<h2><b>Version History</b></h2>

<p>
    <b>1.0.89.0 - September XX, 2013 <font color="red">(release scheduled)</font></b>
</p>
<ul>
    <li>Updated to <a href="http://www.sqlite.org/src/info/trunk">SQLite 3.8.1</a>.</li>
</ul>
<p>
    <b>1.0.88.0 - August 7, 2013</b>
</p>
<ul>
    <li>Various fixes to managed virtual table integration infrastructure.</li>
    <li>Implement workaround for an incorrect PROCESSOR_ARCHITECTURE being reported. Fix for [9ac9862611].</li>