http://www.varlena.com/GeneralBits/107.php has an explanation of the statistics views pg_stat*. Perhaps those would help. --elein elein@xxxxxxxxxxx On Wed, May 11, 2005 at 04:12:11PM -0700, Marc Munro wrote: > On a 7.3 production system with limited downtime available, we can > rarely take the time to run vaccuum full. From time to time though, > performance of some of the tables becomes an issue and we have to > perform a full vaccum on those tables. > > We'd like to be able to better plan these operations, so: > > Is there a query that will return an estimated row count as well as an > estimated unused tuple count for each table? Right now we're figuring > this stuff out by manually by reading the vacuum report. It'd be nice > to have a query on hand that returns a list of tables with more than 30% > unused and more than 100k rows unused. > > I envision these columns being returned: > > table_name, %unused, tuples, unused_tuples, MB_of_disk > > It looks like the estimated row count can be found in pg_class. I can > figure out the size on disk by looking at the physical files. But how > can I figure out the number of dead tuples without actually doing a > vacuum? > > Thanks. > > __ > Marc Munro > ---------------------------(end of broadcast)--------------------------- TIP 7: don't forget to increase your free space map settings
