"Benjamin Krajmalnik" <kraj@xxxxxxxxxxx> writes: >>> While checking our server, I noticed quite a few files in the pg_clog >>> directory. >>> Is there a maintenance task which can be run to purge the files which >>> are no longer needed? >> VACUUM. If they're not disappearing, you aren't running an adequate >> vacuum regime --- missing out some databases, perhaps? > I have autovacuum turned on with the default settings. Hm. I believe that autovac only does database-wide vacuums when it thinks they're necessary to prevent transaction wraparound failures. Which would mean that it'd let pg_clog grow to something on the order of half a gig before any truncation would happen. That's probably insufficiently aggressive :-( Alvaro, Matthew, any thoughts about improving that? It strikes me that Alvaro's work-in-progress on maintaining per-table xmin info would allow truncation of clog without actually insisting on a database-wide VACUUM, but that's not going to be any help for existing releases. regards, tom lane
