SQLite Release 3.7.16.1 On 2013-03-29 (3.7.16.1)

• Added the PRAGMA foreign_key_check command.
• Added new extended error codes for all SQLITE_CONSTRAINT errors
• Added the SQLITE_READONLY_ROLLBACK extended error code for when a database cannot be opened because it needs rollback recovery but is read-only.
• Added SQL functions unicode(A) and char(X1,...,XN).
• Performance improvements for PRAGMA incremental_vacuum, especially in cases where the number of free pages is greater than what will fit on a single trunk page of the freelist.
• Improved optimization of queries containing aggregate min() or max().
• Enhance virtual tables so that they can potentially use an index when the WHERE clause contains the IN operator.
• Allow indices to be used for sorting even if prior terms of the index are constrained by IN operators in the WHERE clause.
• Enhance the PRAGMA table_info command so that the "pk" column is an increasing integer to show the order of columns in the primary key.
• Enhance the query optimizer to exploit transitive join constraints.
• Performance improvements in the query optimizer.
• Allow the error message from PRAGMA integrity_check to be longer than 20000 bytes.
• Improved name resolution for deeply nested queries.
• Added the test_regexp.c module as a demonstration of how to implement the REGEXP operator.
• Improved error messages in the RTREE extension.
• Enhance the command-line shell so that a non-zero argument to the ".exit" command causes the shell to exit immediately without cleanly shutting down the database connection.
• Improved error messages for invalid boolean arguments to dot-commands in the command-line shell.
• Improved error messages for "foreign key mismatch" showing the names of the two tables involved.
• Remove all uses of umask() in the unix VFS.
• Added the PRAGMA vdbe_addoptrace and PRAGMA vdbe_debug commands.
• Change to use strncmp() or the equivalent instead of memcmp() when comparing non-zero-terminated strings.
• Update cygwin interfaces to omit deprecated API calls.
• Enhance the spellfix1 extension so that the edit distance cost table can be changed at runtime by inserting a string like 'edit_cost_table=TABLE' into the "command" field.
• Bug fix: repair a long-standing problem that could cause incorrect query results in a 3-way or larger join that compared INTEGER fields against TEXT fields in two or more places. Ticket fc7bd6358f
• Bug fix: Issue an error message if the 16-bit reference counter on a view overflows due to an overly complex query.
• Bug fix: Avoid leaking memory on LIMIT and OFFSET clauses in deeply nested UNION ALL queries.
• Bug fix: Make sure the schema is up-to-date prior to running pragmas table_info, index_list, index_info, and foreign_key_list.

• Fix for a bug in the ORDER BY optimizer that was introduced in version 3.7.15 which would sometimes optimize out the sorting step when in fact the sort was required. Ticket a179fe7465
• Fix a long-standing bug in the CAST expression that would recognize UTF16 characters as digits even if their most-significant-byte was not zero. Ticket 689137afb6da41.
• Fix a bug in the NEAR operator of FTS3 when applied to subfields. Ticket 38b1ae018f.
• Fix a long-standing bug in the storage engine that would (very rarely) cause a spurious report of an SQLITE_CORRUPT error but which was otherwise harmless. Ticket 6bfb98dfc0c.
• The SQLITE_OMIT_MERGE_SORT option has been removed. The merge sorter is now a required component of SQLite.
• Fixed lots of spelling errors in the source-code comments
• SQLITE_SOURCE_ID: "2013-03-29 13:44:34 527231bc67285f01fb18d4451b28f61da3c4e39d"
• SHA1 for sqlite3.c: 7a91ceceac9bcf47ceb8219126276e5518f7ff5a

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