database/postgres
1
0
Fork 0
mirror of https://github.com/postgres/postgres.git synced 2025-06-16 06:01:02 +03:00
Code Activity

Fix estimate_num_groups() to not fail on PlaceHolderVars, per report from

Browse Source 
Stefan Kaltenbrunner.  The most reasonable behavior (at least for the near
term) seems to be to ignore the PlaceHolderVar and examine its argument
instead.  In support of this, change the API of pull_var_clause() to allow
callers to request recursion into PlaceHolderVars.  Currently
estimate_num_groups() is the only customer for that behavior, but where
there's one there may be others.
This commit is contained in:
Tom Lane
2009-04-19 19:46:33 +00:00
parent 3a624e9200
commit 1d97c19a0f
12 changed files with 63 additions and 39 deletions
Download Patch File Download Diff File Expand all files Collapse all files

9
src/backend/utils/adt/selfuncs.c
View File

@ -15,7 +15,7 @@
*
*
* IDENTIFICATION
* $PostgreSQL: pgsql/src/backend/utils/adt/selfuncs.c,v 1.259 2009/02/15 20:16:21 tgl Exp $
* $PostgreSQL: pgsql/src/backend/utils/adt/selfuncs.c,v 1.260 2009/04/19 19:46:33 tgl Exp $
*
*-------------------------------------------------------------------------
*/
@ -2984,9 +2984,12 @@ estimate_num_groups(PlannerInfo *root, List *groupExprs, double input_rows)
ReleaseVariableStats(vardata);
/*
* Else pull out the component Vars
* Else pull out the component Vars. Handle PlaceHolderVars by
* recursing into their arguments (effectively assuming that the
* PlaceHolderVar doesn't change the number of groups, which boils
* down to ignoring the possible addition of nulls to the result set).
*/
varshere = pull_var_clause(groupexpr, true);
varshere = pull_var_clause(groupexpr, PVC_RECURSE_PLACEHOLDERS);
/*
* If we find any variable-free GROUP BY item, then either it is a