Simon Willison’s Weblog

Optimizing SQLite for servers (via) Sylvain Kerkour’s comprehensive set of lessons learned running SQLite for server-based applications.

There’s a lot of useful stuff in here, including detailed coverage of the different recommended PRAGMA settings.

There was also a tip I haven’t seen before about “BEGIN IMMEDIATE” transactions:

“By default, SQLite starts transactions in DEFERRED mode: they are considered read only. They are upgraded to a write transaction that requires a database lock in-flight, when query containing a write/update/delete statement is issued.

The problem is that by upgrading a transaction after it has started, SQLite will immediately return a SQLITE_BUSY error without respecting the busy_timeout previously mentioned, if the database is already locked by another connection.

This is why you should start your transactions with BEGIN IMMEDIATE instead of only BEGIN. If the database is locked when the transaction starts, SQLite will respect busy_timeout.” # 31st March 2024, 8:16 pm

Announcing DuckDB 0.10.0. Somewhat buried in this announcement: DuckDB has Fixed-Length Arrays now, along with array_cross_product(a1, a2), array_cosine_similarity(a1, a2) and array_inner_product(a1, a2) functions.

This means you can now use DuckDB to find related content (and other tricks) using vector embeddings!

Also notable: “DuckDB can now attach MySQL, Postgres, and SQLite databases in addition to databases stored in its own format. This allows data to be read into DuckDB and moved between these systems in a convenient manner, as attached databases are fully functional, appear just as regular tables, and can be updated in a safe, transactional manner.” # 13th February 2024, 5:57 pm

SQLite 3.45. Released today. The big new feature is JSONB support, a new, specific-to-SQLite binary internal representation of JSON which can provide up to a 3x performance improvement for JSON-heavy operations, plus a 5-10% saving it terms of bytes stored on disk. # 15th January 2024, 8:15 pm