Horton

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

Tom Lane <tgl@sss.pgh.pa.us>

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From: Tom Lane <tgl@sss.pgh.pa.us>
To: Andres Freund <andres@anarazel.de>
Cc: Michael Paquier <michael.paquier@gmail.com>, PostgreSQL mailing lists <pgsql-hackers@postgresql.org>
Date: 2017-09-29T21:56:10Z
Lists: pgsql-hackers 
Andres Freund <andres@anarazel.de> writes:
> Does anybody have an opinion on whether we'll want to convert examples
> like testlibpq3.c (included in libpq.sgml) too? I'm inclined not to,
> because currently using pg_bswap.h requires c.h presence (just for a few
> typedefs and configure data).  There's also not really a pressing need.

We certainly mustn't encourage libpq users to start depending on c.h,
so let's leave that alone.

			regards, tom lane

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.