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| author | Tom Lane <tgl@sss.pgh.pa.us> | 2016-08-24 14:37:51 -0400 |
|---|---|---|
| committer | Tom Lane <tgl@sss.pgh.pa.us> | 2016-08-24 14:37:51 -0400 |
| commit | 3570ea4248caafcd44d015eaaf7f5924e2b58781 (patch) | |
| tree | 896fc1f52801f06cc970ca3638fe35afa9cd2841 /src/backend/nodes/outfuncs.c | |
| parent | 9942376a5b61c824daf653e6aca0bf5c8516f7ab (diff) | |
Fix improper repetition of previous results from a hashed aggregate.
ExecReScanAgg's check for whether it could re-use a previously calculated
hashtable neglected the possibility that the Agg node might reference
PARAM_EXEC Params that are not referenced by its input plan node. That's
okay if the Params are in upper tlist or qual expressions; but if one
appears in aggregate input expressions, then the hashtable contents need
to be recomputed when the Param's value changes.
To avoid unnecessary performance degradation in the case of a Param that
isn't within an aggregate input, add logic to the planner to determine
which Params are within aggregate inputs. This requires a new field in
struct Agg, but fortunately we never write plans to disk, so this isn't
an initdb-forcing change.
Per report from Jeevan Chalke. This has been broken since forever,
so back-patch to all supported branches.
Andrew Gierth, with minor adjustments by me
Report: <CAM2+6=VY8ykfLT5Q8vb9B6EbeBk-NGuLbT6seaQ+Fq4zXvrDcA@mail.gmail.com>
Diffstat (limited to 'src/backend/nodes/outfuncs.c')
| -rw-r--r-- | src/backend/nodes/outfuncs.c | 1 |
1 files changed, 1 insertions, 0 deletions
diff --git a/src/backend/nodes/outfuncs.c b/src/backend/nodes/outfuncs.c index 01b2d6d2d4a..55d4d9b74b9 100644 --- a/src/backend/nodes/outfuncs.c +++ b/src/backend/nodes/outfuncs.c @@ -642,6 +642,7 @@ _outAgg(StringInfo str, Agg *node) appendStringInfo(str, " %u", node->grpOperators[i]); WRITE_LONG_FIELD(numGroups); + WRITE_BITMAPSET_FIELD(aggParams); } static void |