Hi, With the new request-based pgstat reading mechanism, it is easy to fix an autovacuum "bug". Basically for an autovac worker the delay is reduced, so that the data is very fresh. Patch attached.
-- Alvaro Herrera http://www.CommandPrompt.com/ The PostgreSQL Company - Command Prompt, Inc.
*** src/backend/postmaster/autovacuum.c 2 Nov 2008 21:24:52 -0000 1.85 --- src/backend/postmaster/autovacuum.c 3 Nov 2008 16:39:10 -0000 *************** *** 2149,2156 **** * It could have changed if something else processed the table while * we weren't looking. * ! * FIXME we ignore the possibility that the table was finished being ! * vacuumed in the last 500ms (PGSTAT_STAT_INTERVAL). This is a bug. */ MemoryContextSwitchTo(AutovacMemCxt); tab = table_recheck_autovac(relid, table_toast_map); --- 2149,2157 ---- * It could have changed if something else processed the table while * we weren't looking. * ! * Note: we have a special case in pgstat code to ensure that the stats ! * we read are as up-to-date as possible, to avoid the problem that ! * somebody just finished vacuuming this table. */ MemoryContextSwitchTo(AutovacMemCxt); tab = table_recheck_autovac(relid, table_toast_map); *** src/backend/postmaster/pgstat.c 3 Nov 2008 01:17:08 -0000 1.182 --- src/backend/postmaster/pgstat.c 3 Nov 2008 16:37:13 -0000 *************** *** 3389,3396 **** * PGSTAT_STAT_INTERVAL; and we don't want to lie to the collector about * what our cutoff time really is. */ ! min_ts = TimestampTzPlusMilliseconds(GetCurrentTimestamp(), ! -PGSTAT_STAT_INTERVAL); /* * Loop until fresh enough stats file is available or we ran out of time. --- 3389,3400 ---- * PGSTAT_STAT_INTERVAL; and we don't want to lie to the collector about * what our cutoff time really is. */ ! if (IsAutoVacuumWorkerProcess()) ! min_ts = TimestampTzPlusMilliseconds(GetCurrentTimestamp(), ! -PGSTAT_RETRY_DELAY); ! else ! min_ts = TimestampTzPlusMilliseconds(GetCurrentTimestamp(), ! -PGSTAT_STAT_INTERVAL); /* * Loop until fresh enough stats file is available or we ran out of time.
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