pgsql: Fix tsmatchsel() to account properly for null rows.

Lists: pgsql-committers
From: Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us>
To: pgsql-committers(at)postgresql(dot)org
Subject: pgsql: Fix tsmatchsel() to account properly for null rows.
Date: 2011-02-18 00:01:15
Message-ID: E1PqDmd-0002pT-He@gemulon.postgresql.org
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Lists: pgsql-committers

Fix tsmatchsel() to account properly for null rows.

ts_typanalyze.c computes MCE statistics as fractions of the non-null rows,
which seems fairly reasonable, and anyway changing it in released versions
wouldn't be a good idea. But then ts_selfuncs.c has to account for that.
Failure to do so results in overestimates in columns with a significant
fraction of null documents. Back-patch to 8.4 where this stuff was
introduced.

Jesper Krogh

Branch
------
REL9_0_STABLE

Details
-------
http://git.postgresql.org/pg/commitdiff/848cd3289e4d08f9a3c78f654ceb6e3f754e1dd3

Modified Files
--------------
src/backend/tsearch/ts_selfuncs.c | 6 ++++++
src/include/catalog/pg_statistic.h | 2 ++
2 files changed, 8 insertions(+), 0 deletions(-)