Horton

Re: Numeric multiplication overflow errors

David Rowley <dgrowleyml@gmail.com>

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From: David Rowley <dgrowleyml@gmail.com>
To: Dean Rasheed <dean.a.rasheed@gmail.com>
Cc: PostgreSQL Hackers <pgsql-hackers@lists.postgresql.org>
Date: 2021-07-01T10:44:46Z
Lists: pgsql-hackers 
On Thu, 1 Jul 2021 at 22:03, Dean Rasheed <dean.a.rasheed@gmail.com> wrote:
> One other thing I'm wondering about is back-patching. I was originally
> thinking of these as back-patchable bug fixes, but changing the binary
> format of the aggregate serialization states feels dodgy for a
> back-patch.

I was wondering about that too. I'm not sure if any extensions might
be using serial/deserial functions to communicate over multiple
servers. As far as I know, Citus does not do this and implements
aggregates like AVG(c) over multi-nodes with SUM(c) + COUNT(c). I'm
pretty sure Citus is not the only extension doing that kind of work.
So perhaps other people are using the serial/deserial functions.

David

Commits

  1. Fix numeric_mul() overflow due to too many digits after decimal point.

  2. Prevent numeric overflows in parallel numeric aggregates.