Re: BUG #11033: 'pg_dump -a' much slower than 'pg_dump'

On Sat, Oct 11, 2014 at 2:47 PM, Andres Freund <andres(at)2ndquadrant(dot)com>
wrote:

> On 2014-10-11 17:26:59 -0400, Bruce Momjian wrote:
> > On Fri, Jul 25, 2014 at 12:10:52AM +0000, joe(at)tanga(dot)com wrote:
> > > The following bug has been logged on the website:
> > >
> > > Bug reference: 11033
> > > Logged by: Joe Van Dyk
> > > Email address: joe(at)tanga(dot)com
> > > PostgreSQL version: 9.3.5
> > > Operating system: Ubuntu 12.04
> > > Description:
> > >
> > > I've got a small database that takes about 0.8 seconds to dump with
> > > 'pg_dump' and about 11 seconds to dump with 'pg_dump -a'.
> > >
> > > I've narrowed it down to the foreign key constraints in the database,
> if
> > > those are removed, then 'pg_dump -a' becomes fast again.
> > >
> > > I can't come up with an artificial test case. I can reproduce it using
> our
> > > company's db schema. I don't want to publicly post that schema to the
> > > mailing list, but I'd be happy to send the schema that shows the
> problem to
> > > someone privately.
> > >
> > > I can reproduce the problem in 9.3.4 and 9.4.beta1.
> >
> > Wow, that is certainly odd.
>
> There've been a couple cases of that where the dependency resolution
> gets more complex for data only dumps because of the added dependencies
> that try to get the order right to not violate foreign keys. IIRC Tom
> fixed a couple performance problems recently.
> Yep, 51fc6133488a80a1310972b8a0ad20aca13f5b02.
>
> Joe, can you check with some more recent version? Unfortunately that fix
> got committed after 9.3.5. 9.4 beta3 should be fine.
>

I've been using the 9.3-stable branch for the past few months (as a result
of needing this fix), this problem has gone away as far as I can tell.

Joe