On Tue, Aug 30, 2005 at 05:35:13PM +0200, Bohdan Linda wrote: > > Is there any way how to detect running command VACUUM by reading pg_* tables? If you have stats_command_string enabled then you could query pg_stat_activity, but be aware that the results will be stale by the time you see them (there's a slight lag in updating the stats tables, and a VACUUM might start or complete immediately after you issue the query but before you read the results). This method is therefore unreliable. > The idea is to detectect when table is not accessible due maintainance. In modern versions of PostgreSQL a plain VACUUM (without FULL) should have little impact on a table's accessibility unless you're doing something that needs a strong lock (DDL, etc.). But VACUUM FULL and a few other commands do prevent other transactions from accessing a table, so if you want to check for accessibility then you need to check for more than just VACUUM. You might be able to use statement_timeout to make statements fail if they take longer than expected, and infer from the failure that the table is unavailable. But again, that information could be stale by the time you see it -- the table might become available immediately after you decide that it isn't. What problem are you trying to solve? If we knew what you're really trying to do then we might be able to make suggestions. -- Michael Fuhr ---------------------------(end of broadcast)--------------------------- TIP 2: Don't 'kill -9' the postmaster
