> I make a guess I've got this due to parallel running of a program making > bulk INSERTs/UPDATEs into that table. Mmm...I need a way to avoid the big > number of unused pages in such a case. LOCK TABLE?
Only UPDATEs and DELETEs (and rolled back INSERTs) cause unused pages. The trick for other people was to run very frequent 'VACUUM goods;' (like every 15 seconds) on tables when relatively few rows (in small tables) where constantly beeing updated (e.g. counters/balances). It might be sufficient in your case though to do the 'VACUUM goods;' after every bulk UPDATE, like Christopher suggested. A concurrent vacuum won't help if each bulk update is done in one single transaction. Andreas ---------------------------(end of broadcast)--------------------------- TIP 5: Have you checked our extensive FAQ? http://www.postgresql.org/users-lounge/docs/faq.html
