Horton

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

Michael Paquier <michael.paquier@gmail.com>

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From: Michael Paquier <michael.paquier@gmail.com>
To: Andres Freund <andres@anarazel.de>
Cc: PostgreSQL mailing lists <pgsql-hackers@postgresql.org>
Date: 2017-09-27T23:15:37Z
Lists: pgsql-hackers 
On Thu, Sep 28, 2017 at 2:20 AM, Andres Freund <andres@anarazel.de> wrote:
> This'll allow the later patches to allow the compiler to perform the
> relevant optimizations. It also allows to optimize e.g. pq_sendint64()
> to avoid having to do multiple byteswaps.

I guess that you could clean up the 8-byte duplicate implementations
in pg_rewind's libpq_fetch.c (pg_recvint64) and in pg_basebackup's
streamutil.c (fe_recvint64) at the same time, right?
-- 
Michael

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.