SQL As Understood By SQLite

REINDEX

sql-statement ::= REINDEX collation name
sql-statement ::= REINDEX [database-name .] table/index-name

The REINDEX command is used to delete and recreate indices from scratch. This is useful when the definition of a collation sequence has changed.

In the first form, all indices in all attached databases that use the named collation sequence are recreated. In the second form, if [database-name.]table/index-name identifies a table, then all indices associated with the table are rebuilt. If an index is identified, then only this specific index is deleted and recreated.

If no database-name is specified and there exists both a table or index and a collation sequence of the specified name, then indices associated with the collation sequence only are reconstructed. This ambiguity may be dispelled by always specifying a database-name when reindexing a specific table or index.