database/postgres
1
0
Fork 0
mirror of https://github.com/postgres/postgres.git synced 2025-07-02 09:02:37 +03:00
Code Activity

Improve handling of group-column indexes in GroupingSetsPath.

Browse Source 
Instead of having planner.c compute a groupColIdx array and store it in
GroupingSetsPaths, make create_groupingsets_plan() find the grouping
columns by searching in the child plan node's tlist.  Although that's
probably a bit slower for create_groupingsets_plan(), it's more like
the way every other plan node type does this, and it provides positive
confirmation that we know which child output columns we're supposed to be
grouping on.  (Indeed, looking at this now, I'm not at all sure that it
wasn't broken before, because create_groupingsets_plan() isn't demanding
an exact tlist match from its child node.)  Also, this allows substantial
simplification in planner.c, because it no longer needs to compute the
groupColIdx array at all; no other cases were using it.

I'd intended to put off this refactoring until later (like 9.7), but
in view of the likely bug fix and the need to rationalize planner.c's
tlist handling so we can do something sane with Konstantin Knizhnik's
function-evaluation-postponement patch, I think it can't wait.
This commit is contained in:
Tom Lane
2016-03-08 22:32:03 -05:00
parent a40814d7aa
commit 9e8b99420f
8 changed files with 57 additions and 115 deletions
Download Patch File Download Diff File Expand all files Collapse all files

5
src/backend/optimizer/util/pathnode.c
View File

@ -2438,13 +2438,12 @@ create_agg_path(PlannerInfo *root,
*
* GroupingSetsPath represents sorted grouping with one or more grouping sets.
* The input path's result must be sorted to match the last entry in
* rollup_groupclauses, and groupColIdx[] identifies its sort columns.
* rollup_groupclauses.
*
* 'rel' is the parent relation associated with the result
* 'subpath' is the path representing the source of data
* 'target' is the PathTarget to be computed
* 'having_qual' is the HAVING quals if any
* 'groupColIdx' is an array of indexes of grouping columns in the source data
* 'rollup_lists' is a list of grouping sets
* 'rollup_groupclauses' is a list of grouping clauses for grouping sets
* 'agg_costs' contains cost info about the aggregate functions to be computed
@ -2456,7 +2455,6 @@ create_groupingsets_path(PlannerInfo *root,
Path *subpath,
PathTarget *target,
List *having_qual,
AttrNumber *groupColIdx,
List *rollup_lists,
List *rollup_groupclauses,
const AggClauseCosts *agg_costs,
@ -2487,7 +2485,6 @@ create_groupingsets_path(PlannerInfo *root,
else
pathnode->path.pathkeys = NIL;
pathnode->groupColIdx = groupColIdx;
pathnode->rollup_groupclauses = rollup_groupclauses;
pathnode->rollup_lists = rollup_lists;
pathnode->qual = having_qual;