Tatsuo Ishii <ishii@xxxxxxxxxxxxxx> writes: >> Ok, I modified the part of pg_dump where tremendous number of LOCK >> TABLE are issued. I replace them with single LOCK TABLE with multiple >> tables. With 100k tables LOCK statements took 13 minutes in total, now >> it only takes 3 seconds. Comments? > Shall I commit to master and all supported branches? I'm not excited by this patch. It dodges the O(N^2) lock behavior for the initial phase of acquiring the locks, but it does nothing for the lock-related slowdown occurring in all pg_dump's subsequent commands. I think we really need to get in the server-side fix that Jeff Janes is working on, and then re-measure to see if something like this is still worth the trouble. I am also a tad concerned about whether we might not have problems with parsing memory usage, or some such, with thousands of tables being listed in a single command. regards, tom lane -- Sent via pgsql-performance mailing list (pgsql-performance@xxxxxxxxxxxxxx) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-performance
