Re: [PERFORM] pg_dump and thousands of schemas

Robert Haas <robertmhaas@gmail.com> writes:
> On Thu, Aug 30, 2012 at 4:51 PM, Tom Lane <tgl@sss.pgh.pa.us> wrote:
>> Bruce Momjian <bruce@momjian.us> 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.

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.

            regards, tom lane