On Mon, Nov 5, 2012 at 12:14 PM, Tom Lane <t...@sss.pgh.pa.us> wrote: > Bruce Momjian <br...@momjian.us> writes: >> Magnus reported that a customer with a million tables was finding >> pg_upgrade slow. > > You sure there's not an O(N^2) issue in there somewhere?
There certainly will be before he gets to a million, but it probably doesn't show up yet testing at 2000. He will probably have to hack pg_dump, as discussed here: http://archives.postgresql.org/pgsql-performance/2012-09/msg00003.php > >> I don't see anything unsafe about having pg_upgrade use >> synchronous_commit=off. > > No objection, but this seems unlikely to be better than linear speedup, > with a not-terribly-large constant factor. > > BTW, does pg_upgrade run pg_restore in --single-transaction mode? > That would probably make synchronous_commit moot, at least for that > step. Doing that might make the sync problem better, but would make the N^2 problem worse if upgrading to <= 9.2 . Cheers, Jeff -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
