Re: Performance of aggregates over set-returning functions

From: Tom Lane
Subject: Re: Performance of aggregates over set-returning functions
Date: ,
Msg-id: 2322.1213057044@sss.pgh.pa.us
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In response to: Re: Performance of aggregates over set-returning functions  ("John Smith")
List: pgsql-performance


"John Smith" <> writes:
> Sorry for the long delay in following up on this suggestion. The
> change Tom suggested fixed the performance problems I was seeing, but
> I never ran the full regression suite on the modified code, as
> everything in my performance tests seemed to indicate the bug was
> fixed (i.e, no errors even with --cassert-enabled). When I recently
> ran the regression suite on the "fixed" version of Postgres, the
> "misc" test suite fails with the following error message: "ERROR:
> cache lookup failed for type 2139062143". Is this a manifestation of
> the problem where certain items are being freed too early?

Yup --- something's trying to use memory that's already been freed.
The particular case is evidently a field containing a type OID.

You might be able to get a clue where the problem is by getting a gdb
stack trace back from errfinish(), but this sort of kills my optimism
that the 7.0-era problem is gone ...

            regards, tom lane


pgsql-performance by date:

From: Tom Lane
Date:
Subject: Re: Performance of aggregates over set-returning functions
From: Zoltan Boszormenyi
Date:
Subject: Scalability question