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Collect and use multi-column dependency stats

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Follow on patch in the multi-variate statistics patch series.

CREATE STATISTICS s1 WITH (dependencies) ON (a, b) FROM t;
ANALYZE;
will collect dependency stats on (a, b) and then use the measured
dependency in subsequent query planning.

Commit 7b504eb282 added
CREATE STATISTICS with n-distinct coefficients. These are now
specified using the mutually exclusive option WITH (ndistinct).

Author: Tomas Vondra, David Rowley
Reviewed-by: Kyotaro HORIGUCHI, Álvaro Herrera, Dean Rasheed, Robert Haas
and many other comments and contributions
Discussion: https://postgr.es/m/56f40b20-c464-fad2-ff39-06b668fac47c@2ndquadrant.com
This commit is contained in:
Simon Riggs
2017-04-05 18:00:42 -04:00
parent 00b6b6feb1
commit 2686ee1b7c
31 changed files with 2035 additions and 79 deletions
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12
src/backend/optimizer/util/plancat.c
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@@ -1308,6 +1308,18 @@ get_relation_statistics(RelOptInfo *rel, Relation relation)
stainfos = lcons(info, stainfos);
}
if (statext_is_kind_built(htup, STATS_EXT_DEPENDENCIES))
{
StatisticExtInfo *info = makeNode(StatisticExtInfo);
info->statOid = statOid;
info->rel = rel;
info->kind = STATS_EXT_DEPENDENCIES;
info->keys = bms_copy(keys);
stainfos = lcons(info, stainfos);
}
ReleaseSysCache(htup);
bms_free(keys);
}