aus dem Designdokument zu SQLite 4
SQLite4 is a compact, self-contained, zero-adminstration, ACID database engine in a library, just like SQLite3, but with an improved interface and file format. The run-time environment is encapsulated in an object. A greatly simplified Key/Value storage engine is used: A single large key space - not separate key spaces for each table and index as in SQLite3. Keys sort in lexicographical order. Multiple storage engines, interchangeable at run-time. Default on-disk storage engine uses a log-structured merge database. The PRIMARY KEY of a table really is used as the key to the storage engine. Decimal arithmetic is used. Foreign key constraints and recursive triggers are on by default. Covering indices can be declared explicitly.
Der wichtigste Satz:
SQLite4 is an alternative, not a replacement, for SQLite3. SQLite3 is not going away. SQLite3 and SQLite4 will be supported in parallel. The SQLite3 legacy will not be abandoned. SQLite3 will continue to be maintained and improved. But designers of new systems will now have the option to select SQLite4 instead of SQLite3 if desired.
SQLite 3 wird also parallel weiter entwickelt bzw. werden Änderungen wohl nachgezogen.
Eine wichtige Neuerung in SQLite 4 ist der “echte” Primary Key, da ja in SQLite 3 die RowID als Primary Key hergenommen wurde. Das sollte einiges an Performance-Zuwachs bringen.
Mal sehen wann sich die Neuerungen auch auf den Mobil-Plattformen Android und iOS wiederfinden werden.