On Thu, Nov 29, 2012 at 12:59:19PM -0500, Bruce Momjian wrote: > I have polished up the patch (attached) and it is ready for application > to 9.3.
Applied. --------------------------------------------------------------------------- > Since there is no pg_dump/pg_restore pipe parallelism, I had the old > cluster create per-database dump files, so I don't need to have the old > and new clusters running at the same time, which would have required two > port numbers and make shared memory exhaustion more likely. > > We now create a dump file per database, so thousands of database dump > files might cause a performance problem. > > This also adds status output so you can see the database names as their > schemas are dumped and restored. This was requested by users. > > I retained custom mode for pg_dump because it is measurably faster than > text mode (not sure why, psql overhead?): > > git -Fc -Fp > 1 11.04 11.08 11.02 > 1000 22.37 19.68 21.64 > 2000 32.39 28.62 31.40 > 4000 56.18 48.53 51.15 > 8000 105.15 81.23 91.84 > 16000 227.64 156.72 177.79 > 32000 542.80 323.19 371.81 > 64000 1711.77 789.17 865.03 > > Text dump files are slightly easier to debug, but probably not by much. > > Single-transaction restores were recommended to me over a year ago (by > Magnus?), but I wanted to get pg_upgrade rock-solid before doing > optimization, and now is the right time to optimize. > > One risk of single-transaction restores is max_locks_per_transaction > exhaustion, but you will need to increase that on the old cluster for > pg_dump anyway because that is done a single transaction, so the only > new thing is that the new cluster might also need to adjust > max_locks_per_transaction. > > I was able to remove split_old_dump() because pg_dumpall now produces a > full global restore file and we do database dumps separately. -- Bruce Momjian <br...@momjian.us> http://momjian.us EnterpriseDB http://enterprisedb.com + It's impossible for everything to be true. + -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
