On Sun, Sep 2, 2012 at 5:39 PM, Jeff Janes <jeff.janes@xxxxxxxxx> wrote: > On Thu, Aug 30, 2012 at 8:17 PM, Tom Lane <tgl@xxxxxxxxxxxxx> wrote: >> Robert Haas <robertmhaas@xxxxxxxxx> writes: >>> On Thu, Aug 30, 2012 at 4:51 PM, Tom Lane <tgl@xxxxxxxxxxxxx> wrote: >>>> Bruce Momjian <bruce@xxxxxxxxxx> writes: >>>>> On Thu, May 31, 2012 at 09:20:43AM +0900, Tatsuo Ishii wrote: >>>>>> 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? >> >>>>> Was this applied? >> >>>> No, we fixed the server side instead. >> >>> But only for 9.2, right? So people running back branches are still screwed. >> >> Yeah, but they're screwed anyway, because there are a bunch of O(N^2) >> behaviors involved here, not all of which are masked by what Tatsuo-san >> suggested. > > All of the other ones that I know of were associated with pg_dump > itself, and since it is recommended to run the newer version of > pg_dump against the older version of the server, no back patching > would be necessary to get the benefits of those particular fixes. > >> Six months or a year from now, we might have enough confidence in that >> batch of 9.2 fixes to back-port them en masse. Don't want to do it >> today though. > > > What would be the recommendation for people trying to upgrade, but who > can't get their data out in a reasonable window? > > Putting Tatsuo-san's change into a future pg_dump might be more > conservative than back-porting the server's Lock Table change to the > server version they are trying to get rid of. What he said. -- Robert Haas EnterpriseDB: http://www.enterprisedb.com The Enterprise PostgreSQL Company -- Sent via pgsql-performance mailing list (pgsql-performance@xxxxxxxxxxxxxx) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-performance
