My driver (Wasm based) does many of these things by default.

Foreign keys are default enabled, default synchronous mode is FULL for rollback and NORMAL for WAL, shared cache is disabled, the default busy timeout when using database/sql is 60 seconds.

About the default huge busy timeout: my driver can easily afford this because context cancellation actually works and interrupt both long running queries and filesystem locks. I don't think the mattn driver can use a (e.g.) WithDeadline(100ms) context to interrupt early a connection blocked on a busy timeout of 5 seconds: your goroutine will be stuck in a Cgo loop without anything to interrupt it.

Doing this properly requires a custom busy handler, the overhead of which might be to big for Cgo (not sure). Having done this, I also implemented the Ruby approach to improve tail latencies: https://fractaledmind.com/2023/12/06/sqlite-on-rails-improvi...

Another important thing that I don't think mattn does, is have a default transaction "kind" and then allow specific transactions to override it. For SQLite, arguably, the default transaction should be immediate, with only read-only transactions being deferred. I make it possible to pick the transaction type with BeginTx.

Also, recommendations on PRAGMA optimize vary. If you do it when opening connections, you're supposed to use specific flags: optimize uses previous work by the connection to guide what to do, and there's none at this point. This also adds latency to opening connections. Another possibility is doing it when a connection is closed. My driver makes adding a close callback easy.

https://github.com/ncruces/go-sqlite3

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jacob2161 a day ago | parent [-]

Thanks for the comments. I'm a fan.

Yeah, I think "PRAGMA optimize" here on startup is basically a no-op and only costs microseconds but I should just remove it.

Seems like the ideal thing is to spawn a goroutine and run optimize periodically. Many Go daemons I run will have uptime measured in months so running on shutdown isn't super useful there.

Another one I might add is running `PRAGMA wal_checkpoint(PASSIVE)` periodically from a goroutine, which is something I've done in some of my daemons. Because otherwise a random write suffers from increased latency due to having to checkpoint.

Probably makes sense to open a dedicated read/write connection just for running `PRAGMA wal_checkpoint(PASSIVE)` at some regular interval to keep ahead of any autocheckpointing?

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ncruces a day ago | parent [-]

> Seems like the ideal thing is to spawn a goroutine and run optimize periodically. Many Go daemons I run will have uptime measured in months so running on shutdown isn't super useful there.

Connections don't necessarily need to be kept forever. Between SetConnMaxLifetime/SetConnMaxIdleTime that's one way of periodically optimizing from “warm” connections. But doing it on a timer from a fresh goroutine is another.

	▲	jacob2161 a day ago \| parent [-]
		That's a good point too. It seems a bit weird to me to garbage collect connections that I know I'll just recreate in most cases, especially when they're so cheap and limited in number. Cycling connections may cover for certain classes of bugs but I dislike doing things for this reason, but maybe there are others. I'll put some thinking/testing into it at some point. Thanks!