(TLDR at the end) I spent the past two days trying to optimize one of the SQLite DBs and operations on them for what would be a rather extreme scenario for us, though not impossible if we assume bugs (my thinking is if it works under these conditions, prod will be a breeze). Unfortunately my effort…

[image] siiky: The other is that when a given statement takes more time than the :timeout, an error is logged (suggesting the execution was canceled), but it actually continues through to the end and even returns, because no error is raised. Here are logs showing this (used timeout: 100 to force…

I ran into similar issues recently. A lot depends on your SQLite configuration - could you share yours? You should keep in mind that only one connection can write to the database, while multiple concurrent reads are possible, but only under certain settings. For example, if you rely on a **…

[image] LostKobrakai: The current exqlite implementation cannot stop queries. I’d seen that but hadn’t quite connected it to these questions! If queries can’t be stopped anyway, what would I lose by setting a default of timeout: :infinity? Because in practice, from the point of view of the DB…

Thanks for the tips, I’d missed the shared cache thing, and the read_uncommitted PRAGMA. [image] funboy: A lot depends on your SQLite configuration - could you share yours? In dev I’m using: database: Path.expand(filename, databases_directory), pool_size: 5, stacktrace: true, …

Thanks for the tips, I’d missed the shared cache thing, and the read_uncommitted PRAGMA. I see u are using file-based db - so u don’t need them More problematic is the most costly operation, which is cleanup To address the issue with the long cleanup query, you could try optimizing it or spli…

[image] siiky: If queries can’t be stopped anyway, what would I lose by setting a default of timeout: :infinity? Because in practice, from the point of view of the DB, that’s already reality. I‘d argue that for the exqlite driver this is a reasonable choice infeed.

[image] LostKobrakai: [image] siiky: What influences the idle time? Is it even worrying? (maybe not if only db time counts for the timeout?) This is for judging how busy your pool of connections is. Problematic are small idle values, not large ones. Is there any more information about …

[image] funboy: To address the issue with the long cleanup query, you could try optimizing it or splitting it into several smaller queries It initially had a connection checked out to run the three steps, now it doesn’t. I have also tried splitting the select from the delete (SELECT id ... an…

The DBConnection pool focuses on tranditional databases where additional connections have real cost. So you want to find the sweetspot of just enough, where connections are well utilized but not overloaded. Hence :idle is an interesting metric to track. For sqlite you can read the issue I posted abo…

Help with SQLite reliability (idle time & timeout errors)

Questions & Help Questions

LostKobrakai March 12, 2026, 5:53pm 7

I‘d argue that for the exqlite driver this is a reasonable choice infeed.