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| author | Tom Lane <tgl@sss.pgh.pa.us> | 2006-09-20 19:50:21 +0000 |
|---|---|---|
| committer | Tom Lane <tgl@sss.pgh.pa.us> | 2006-09-20 19:50:21 +0000 |
| commit | bfd1ffa948e676f0587239a36e71f15690ef2cde (patch) | |
| tree | 0f29dd2001a93fa708142d94f62f940967b09f6b /src/backend/access/gist/gistproc.c | |
| parent | 06b33f0ee8481a83f9e62c0fc77ab16afb4aeec1 (diff) | |
| download | postgresql-bfd1ffa948e676f0587239a36e71f15690ef2cde.tar.gz postgresql-bfd1ffa948e676f0587239a36e71f15690ef2cde.zip | |
Change patternsel (LIKE/regex selectivity estimation) so that if there
is a large enough histogram, it will use the number of matches in the
histogram to derive a selectivity estimate, rather than the admittedly
pretty bogus heuristics involving examining the pattern contents. I set
'large enough' at 100, but perhaps we should change that later. Also
apply the same technique in contrib/ltree's <@ and @> estimator. Per
discussion with Stefan Kaltenbrunner and Matteo Beccati.
Diffstat (limited to 'src/backend/access/gist/gistproc.c')
0 files changed, 0 insertions, 0 deletions