Re: Binary search in fmgr_isbuiltin() is a bottleneck.

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

From: Tom Lane <tgl@sss.pgh.pa.us>
To: Andres Freund <andres@anarazel.de>
Cc: Robert Haas <robertmhaas@gmail.com>, Jeevan Ladhe <jeevan.ladhe@enterprisedb.com>, PostgreSQL Developers <pgsql-hackers@postgresql.org>
Date: 2017-10-02T21:57:51Z
Lists: pgsql-hackers
Andres Freund <andres@anarazel.de> writes:
> Done that way. It's a bit annoying, because we've to take care to
> initialize the "unused" part of the array with a valid signalling it's
> an unused mapping. Can't use 0 for that because fmgr_builtins[0] is a
> valid entry.

The prototype code I posted further upthread just used -1 as the "unused"
marker.  There's no reason the array can't be int16 rather than uint16,
and "if (index < 0)" is probably a faster test anyway.

			regards, tom lane


Commits

  1. Replace binary search in fmgr_isbuiltin with a lookup array.

  2. Add inline murmurhash32(uint32) function.