Re: Optimizing pg_trgm makesign() (was Re: WIP: Fast GiST index build) - Mailing list pgsql-hackers

From Kevin Grittner
Subject Re: Optimizing pg_trgm makesign() (was Re: WIP: Fast GiST index build)
Date
Msg-id 4E7F652A02000025000416DB@gw.wicourts.gov
Whole thread Raw
Responses Re: Re: Optimizing pg_trgm makesign() (was Re: WIP: Fast GiST index build)
List pgsql-hackers
This is a review of the patch at this CF location:
https://commitfest.postgresql.org/action/patch_view?id=598
as posted here:
http://archives.postgresql.org/message-id/4E04C099.3020604@enterprisedb.com
This patch applied cleanly and compiled without warning.  It
performed correctly.  Since the patch modifies one function which has
one input and one output (through a pointer parameter), with no other
side effects, it has low risk of surprising problems.
It is strictly a performance patch, and accomplishes its goals.  I
ran the entire dictionary through the patched and unpatched versions
five times each (using the supplied debugging patch) and saw no
changes to the behavior of the function -- identical results every
time.  I ran performance tests with building and reindexing the
sorted dictionary, a randomly ordered dictionary, a randomly ordered
dictionary with the entries randomly truncated to 0 to 3 characters,
and a large README file -- five times each with and without the
patch.  The patch was a clear winner with all of those except the
truncated dictionary, where the difference we well within the noise
(0.05% difference summing five runs when individual runs could vary
by up to about 4%).
While there was no reason to believe it could affect search
performance, I tested that anyway, and found no difference.
Once this message shows up on the list (so I can retrieve the message
ID) I will mark this "Ready for Committer".
-Kevin



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