Horton

Re: SendRowDescriptionMessage() is slow for queries with a lot of columns

Robert Haas <robertmhaas@gmail.com>

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From: Robert Haas <robertmhaas@gmail.com>
To: Andres Freund <andres@anarazel.de>
Cc: Alvaro Herrera <alvherre@alvh.no-ip.org>, "pgsql-hackers@postgresql.org" <pgsql-hackers@postgresql.org>
Date: 2017-10-11T19:36:25Z
Lists: pgsql-hackers 
On Wed, Oct 11, 2017 at 2:47 PM, Andres Freund <andres@anarazel.de> wrote:
>> If do nothing, it's unlikely we'd ever get rid of the compat function.
>
> I think that's ok.

Yeah.  I mean, it seems similar to what happened with heap_formtuple:
the last in-tree users of that function went away in 8.4 (902d1cb35)
but we didn't remove the function itself until 9.6 (726117243).  It
didn't really hurt anyone in the meantime; it was just a function
that, in most installs, was probably never called.  I think we should
do the same thing here: plan to keep the old functions around at least
until 11 is out of support, maybe longer, and not worry about it very
much.

-- 
Robert Haas
EnterpriseDB: http://www.enterprisedb.com
The Enterprise PostgreSQL Company

Commits

  1. Replace remaining uses of pq_sendint with pq_sendint{8,16,32}.

  2. Improve performance of SendRowDescriptionMessage.

  3. Use one stringbuffer for all rows printed in printtup.c.

  4. Add configure infrastructure to detect support for C99's restrict.

  5. Add more efficient functions to pqformat API.

  6. Allow to avoid NUL-byte management for stringinfos and use in format.c.

  7. Replace most usages of ntoh[ls] and hton[sl] with pg_bswap.h.

  8. Extend & revamp pg_bswap.h infrastructure.