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  • orca@orcas.enjoying.yachts
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    2 months ago

    but Lemmy really fucked up their database performance somehow.

    Can confirm. I spent like 4 hours one day configuring auto vacuum and other shit on my Lemmy DB because it was bloating to hell and eating up resources. Runs much smoother now but it was a massive PITA to get there.

      • orca@orcas.enjoying.yachts
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        1 day ago

        I can’t remember exactly what I did but enabling autovacuum was one of the big ones. I’ll try to provide some info below:

        Walks through VACUUM and autovacuum - https://oneuptime.com/blog/post/2026-01-25-use-vacuum-analyze-postgresql/view

        How to see if autovacuum is already enabled (these are commands you’d run while in sql):

        SHOW autovacuum;

        View current settings:

        SELECT name, setting FROM pg_settings WHERE name LIKE '%autovacuum%';

        Monitor which tables need attention:

        SELECT schemaname, relname, n_dead_tup, n_live_tup 
        FROM pg_stat_user_tables 
        WHERE n_dead_tup > 1000 
        ORDER BY n_dead_tup DESC;
        

        I wish I had documented it at the time because info about this for Lemmy specifically is pretty lacking. I was in kind of a dire situation though because my disk space had filled up quickly and my system was struggling. A lot of what I did was basic PostgreSQL maintenance stuff, so you should be able to find some general guides for that.

        EDIT: I had Claude help me corral some optimization stuff into a PDF. This is along the lines of what I did to get my db back under control. Make sure to always backup first! https://u.orca.casa/1771250081