System.Data.SQLite

    SQLite.  This pragma is subject to change without notice and is not
    recommended for use by application programs.</p>
  
<a name="pragma_synchronous"></a>
<hr>
    <p><b>PRAGMA </b><i>schema.</i><b>synchronous;
        <br>PRAGMA </b><i>schema.</i><b>synchronous = </b>
          <i>0 | OFF | 1 | NORMAL | 2 | FULL | 3 | EXTRA</i><b>;</b></p>

    <p>Query or change the setting of the "synchronous" flag.
    The first (query) form will return the synchronous setting as an 
    integer.  The second form changes the synchronous setting.
    The meanings of the various synchronous settings are as follows:</p>
    <dl>
    <dt><b>EXTRA</b> (3)</dt>
    <dd>
    EXTRA synchronous is like FULL with the addition that the directory
    containing a <a href="lockingv3.html#rollback">rollback journal</a> is synced after that journal is unlinked
    to commit a transaction in DELETE mode.  EXTRA provides additional
    durability if the commit is followed closely by a power loss.</dd>
    <dt><b>FULL</b> (2)</dt>
    <dd>
    When synchronous is FULL (2), the SQLite database engine will
    use the xSync method of the <a href="vfs.html">VFS</a> to ensure that all content is safely
    written to the disk surface prior to continuing.
    This ensures that an operating system crash or power failure will
    not corrupt the database.
    FULL synchronous is very safe, but it is also slower.  FULL is the
    usual default setting when not in <a href="wal.html">WAL mode</a>.</dd>
    <dt><b>NORMAL</b> (1)</dt>
    <dd>
    When synchronous is NORMAL (1), the SQLite database
    engine will still sync at the most critical moments, but less often
    than in FULL mode.  There is a very small (though non-zero) chance that
    a power failure at just the wrong time could corrupt the database in
    NORMAL mode.  But in practice, you are more likely to suffer
    a catastrophic disk failure or some other unrecoverable hardware
    fault.  NORMAL is the default when in <a href="wal.html">WAL mode</a>.</dd>
    <dt><b>OFF</b> (0)</dt>
    <dd>
    With synchronous OFF (0), SQLite continues without syncing
    as soon as it has handed data off to the operating system.
    If the application running SQLite crashes, the data will be safe, but
    the database might become corrupted if the operating system
    crashes or the computer loses power before that data has been written
    to the disk surface.  On the other hand, commits can be orders of
    magnitude faster with synchronous OFF.
    </dd></dl>
    </p>
 
    <p>In <a href="wal.html">WAL</a> mode when synchronous is NORMAL (1), the WAL file is
    synchronized before each <a href="wal.html#ckpt">checkpoint</a> and the database file is
    synchronized after each completed <a href="wal.html#ckpt">checkpoint</a> and the WAL file
    header is synchronized when a WAL file begins to be reused after
    a checkpoint, but no sync operations occur during most transactions.
    With synchronous=FULL in WAL mode, an additional
    sync operation of the WAL file happens after each transaction commit.
    The extra WAL sync following each transaction help ensure that 
    transactions are durable across a power loss, but they do not aid
    in preserving consistency.
    If durability is not a concern, then synchronous=NORMAL is normally
    all one needs in WAL mode.</p>

    <p>The default setting is usually synchronous=FULL, 
    except in <a href="wal.html">WAL mode</a> when the default is synchronous=NORMAL.
    The <a href="compile.html#extra_durable">SQLITE_EXTRA_DURABLE</a> compile-time option changes the
    default to synchronous=EXTRA.</p>

    <p>See also the <a href="pragma.html#pragma_fullfsync">fullfsync</a> and <a href="pragma.html#pragma_checkpoint_fullfsync">checkpoint_fullfsync</a> pragmas.</p>
<a name="pragma_table_info"></a>
<hr>
    <p><b>PRAGMA </b><i>schema.</i><b>table_info(</b><i>table-name</i><b>);</b></p>
    <p>This pragma returns one row for each column in the named table.
    Columns in the result set include the column name,

forms the reply. The <a href="c3ref/index_info.html">sqlite3_index_info</a> structure looks like this:

<blockquote><pre>
  struct sqlite3_index_info {
    /* Inputs */
    const int nConstraint;     /* Number of entries in aConstraint */
    const struct sqlite3_index_constraint {
       int iColumn;              /* Column constrained.  -1 for ROWID */
       unsigned char op;         /* Constraint operator */
       unsigned char usable;     /* True if this constraint is usable */
       int iTermOffset;          /* Used internally - xBestIndex should ignore */
    } *const aConstraint;      /* Table of WHERE clause constraints */
    const int nOrderBy;        /* Number of terms in the ORDER BY clause */
    const struct sqlite3_index_orderby {
       int iColumn;              /* Column number */

**
** See also: [sqlite3_libversion()],
** [sqlite3_libversion_number()], [sqlite3_sourceid()],
** [sqlite_version()] and [sqlite_source_id()].
*/
#define SQLITE_VERSION        "3.11.0"
#define SQLITE_VERSION_NUMBER 3011000
#define SQLITE_SOURCE_ID      "2016-02-15 17:29:24 3d862f207e3adc00f78066799ac5a8c282430a5f"

/*
** 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

    ** checksums must be recomputed when the transaction is committed.  */
    if( iFirst && (p->pDirty || isCommit==0) ){
      u32 iWrite = 0;
      VVA_ONLY(rc =) sqlite3WalFindFrame(pWal, p->pgno, &iWrite);
      assert( rc==SQLITE_OK || iWrite==0 );
      if( iWrite>=iFirst ){
        i64 iOff = walFrameOffset(iWrite, szPage) + WAL_FRAME_HDRSIZE;
        void *pData;
        if( pWal->iReCksum==0 || iWrite<pWal->iReCksum ){
          pWal->iReCksum = iWrite;
        }
#if defined(SQLITE_HAS_CODEC)
        if( (pData = sqlite3PagerCodec(p))==0 ) return SQLITE_NOMEM;
#else
        pData = p->pData;
#endif
        rc = sqlite3OsWrite(pWal->pWalFd, pData, szPage, iOff);
        if( rc ) return rc;
        p->flags &= ~PGHDR_WAL_APPEND;
        continue;
      }
    }

    iFrame++;

static void fts5SourceIdFunc(
  sqlite3_context *pCtx,          /* Function call context */
  int nArg,                       /* Number of args */
  sqlite3_value **apUnused        /* Function arguments */
){
  assert( nArg==0 );
  UNUSED_PARAM2(nArg, apUnused);
  sqlite3_result_text(pCtx, "fts5: 2016-02-15 17:29:24 3d862f207e3adc00f78066799ac5a8c282430a5f", -1, SQLITE_TRANSIENT);
}

static int fts5Init(sqlite3 *db){
  static const sqlite3_module fts5Mod = {
    /* iVersion      */ 2,
    /* xCreate       */ fts5CreateMethod,
    /* xConnect      */ fts5ConnectMethod,

**
** See also: [sqlite3_libversion()],
** [sqlite3_libversion_number()], [sqlite3_sourceid()],
** [sqlite_version()] and [sqlite_source_id()].
*/
#define SQLITE_VERSION        "3.11.0"
#define SQLITE_VERSION_NUMBER 3011000
#define SQLITE_SOURCE_ID      "2016-02-15 17:29:24 3d862f207e3adc00f78066799ac5a8c282430a5f"

/*
** 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

static void fts5SourceIdFunc(
  sqlite3_context *pCtx,          /* Function call context */
  int nArg,                       /* Number of args */
  sqlite3_value **apUnused        /* Function arguments */
){
  assert( nArg==0 );
  UNUSED_PARAM2(nArg, apUnused);
  sqlite3_result_text(pCtx, "fts5: 2016-02-15 17:29:24 3d862f207e3adc00f78066799ac5a8c282430a5f", -1, SQLITE_TRANSIENT);
}

static int fts5Init(sqlite3 *db){
  static const sqlite3_module fts5Mod = {
    /* iVersion      */ 2,
    /* xCreate       */ fts5CreateMethod,
    /* xConnect      */ fts5ConnectMethod,

        /// forms the reply. The sqlite3_index_info structure looks like this:
        /// </para>
        /// <para><code>
        ///   struct sqlite3_index_info {
        ///     /* Inputs */
        ///     const int nConstraint;     /* Number of entries in aConstraint */
        ///     const struct sqlite3_index_constraint {
        ///        int iColumn;              /* Column constrained.  -1 for ROWID */
        ///        unsigned char op;         /* Constraint operator */
        ///        unsigned char usable;     /* True if this constraint is usable */
        ///        int iTermOffset;          /* Used internally - xBestIndex should ignore */
        ///     } *const aConstraint;      /* Table of WHERE clause constraints */
        ///     const int nOrderBy;        /* Number of terms in the ORDER BY clause */
        ///     const struct sqlite3_index_orderby {
        ///        int iColumn;              /* Column number */