SQLite Release 3.3.0 On 2006-01-10

• CHECK constraints
• IF EXISTS and IF NOT EXISTS clauses on CREATE/DROP TABLE/INDEX.
• DESC indices
• More efficient encoding of boolean values resulting in smaller database files
• More aggressive SQLITE_OMIT_FLOATING_POINT
• Separate INTEGER and REAL affinity
• Added a virtual function layer for the OS interface
• "exists" method added to the TCL interface
• Improved response to out-of-memory errors
• Database cache can be optionally shared between connections in the same thread
• Optional READ UNCOMMITTED isolation (instead of the default isolation level of SERIALIZABLE) and table level locking when database connections share a common cache.

A complete list of SQLite releases in a single page is also available. A detailed history of every check-in is available at http://www.sqlite.org/src/timeline.