On Thu, Sep 4, 2008 at 8:58 PM, Duan Ligong <duanlg@xxxxxxxxxxxxxxxxx> wrote: > Thanks for your reply. > > Greg wrote: >> On Tue, 2 Sep 2008, Duan Ligong wrote: >> > - Does Vacuum delete the old clog files? >> >> Yes, if those transactions are all done. One possibility here is that >> you've got some really long-running transaction floating around that is >> keeping normal clog cleanup from happening. Take a look at the output >> from "select * from pg_stat_activity" and see if there are any really old >> transactions floating around. > > Well, we could not wait so long and just moved the old clog files. > The postgresql system is running well. > But now the size of pg_clog has exceeded 50MB and there > are 457 clog files. That is absolutely not the thing to do. Put them back, and do a dump-restore on the database if you need to save a few hundred megs on the drive. Deleting files from underneath postgresql is a great way to break your database in new and interesting ways which are often fatal to your data.
