Re: pg_dump and thousands of schemas

On Fri, May 25, 2012 at 9:56 AM, Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us> wrote:
> Jeff Janes <jeff(dot)janes(at)gmail(dot)com> writes:
>
>> For dumping entire databases, It looks like the biggest problem is
>> going to be LockReassignCurrentOwner in the server.  And that doesn't
>> seem to be easy to fix, as any change to it to improve pg_dump will
>> risk degrading normal use cases.
>
> I didn't try profiling the server side, but pg_dump doesn't use
> subtransactions so it's not clear to me why LockReassignCurrentOwner
> would get called at all ...

I thought that every select statement in a repeatable read transaction
ran in a separate "portal", and that a portal is a flavor of
subtransaction. Anyway, it does show up at the top of a profile of
the server, so it is getting called somehow.

Cheers,

Jeff