diff options
| -rw-r--r-- | src/backend/optimizer/path/pathkeys.c | 24 | ||||
| -rw-r--r-- | src/test/regress/expected/window.out | 16 | ||||
| -rw-r--r-- | src/test/regress/sql/window.sql | 13 |
3 files changed, 51 insertions, 2 deletions
diff --git a/src/backend/optimizer/path/pathkeys.c b/src/backend/optimizer/path/pathkeys.c index 8b04d40d36d..879dcb4608e 100644 --- a/src/backend/optimizer/path/pathkeys.c +++ b/src/backend/optimizer/path/pathkeys.c @@ -2154,14 +2154,31 @@ right_merge_direction(PlannerInfo *root, PathKey *pathkey) * Because we the have the possibility of incremental sort, a prefix list of * keys is potentially useful for improving the performance of the requested * ordering. Thus we return 0, if no valuable keys are found, or the number - * of leading keys shared by the list and the requested ordering.. + * of leading keys shared by the list and the requested ordering. */ static int pathkeys_useful_for_ordering(PlannerInfo *root, List *pathkeys) { int n_common_pathkeys; - (void) pathkeys_count_contained_in(root->query_pathkeys, pathkeys, + (void) pathkeys_count_contained_in(root->sort_pathkeys, pathkeys, + &n_common_pathkeys); + + return n_common_pathkeys; +} + +/* + * pathkeys_useful_for_windowing + * Count the number of pathkeys that are useful for meeting the + * query's desired sort order for window function evaluation. + */ +static int +pathkeys_useful_for_windowing(PlannerInfo *root, List *pathkeys) +{ + int n_common_pathkeys; + + (void) pathkeys_count_contained_in(root->window_pathkeys, + pathkeys, &n_common_pathkeys); return n_common_pathkeys; @@ -2278,6 +2295,9 @@ truncate_useless_pathkeys(PlannerInfo *root, nuseful2 = pathkeys_useful_for_ordering(root, pathkeys); if (nuseful2 > nuseful) nuseful = nuseful2; + nuseful2 = pathkeys_useful_for_windowing(root, pathkeys); + if (nuseful2 > nuseful) + nuseful = nuseful2; nuseful2 = pathkeys_useful_for_grouping(root, pathkeys); if (nuseful2 > nuseful) nuseful = nuseful2; diff --git a/src/test/regress/expected/window.out b/src/test/regress/expected/window.out index a2867f477f0..9e2f53726f5 100644 --- a/src/test/regress/expected/window.out +++ b/src/test/regress/expected/window.out @@ -4537,6 +4537,22 @@ WHERE first_emp = 1 OR last_emp = 1; sales | 4 | 4800 | 08-08-2007 | 3 | 1 (6 rows) +CREATE INDEX empsalary_salary_empno_idx ON empsalary (salary, empno); +SET enable_seqscan = 0; +-- Ensure no sorting is done and that the IndexScan maintains all pathkeys +-- useful for the final sort order. +EXPLAIN (COSTS OFF) +SELECT salary, empno, row_number() OVER (ORDER BY salary) rn +FROM empsalary +ORDER BY salary, empno; + QUERY PLAN +--------------------------------------------------------------------- + WindowAgg + Window: w1 AS (ORDER BY salary ROWS UNBOUNDED PRECEDING) + -> Index Only Scan using empsalary_salary_empno_idx on empsalary +(3 rows) + +RESET enable_seqscan; -- cleanup DROP TABLE empsalary; -- test user-defined window function with named args and default args diff --git a/src/test/regress/sql/window.sql b/src/test/regress/sql/window.sql index 85fc621c8db..37d837a2f66 100644 --- a/src/test/regress/sql/window.sql +++ b/src/test/regress/sql/window.sql @@ -1522,6 +1522,19 @@ SELECT * FROM FROM empsalary) emp WHERE first_emp = 1 OR last_emp = 1; +CREATE INDEX empsalary_salary_empno_idx ON empsalary (salary, empno); + +SET enable_seqscan = 0; + +-- Ensure no sorting is done and that the IndexScan maintains all pathkeys +-- useful for the final sort order. +EXPLAIN (COSTS OFF) +SELECT salary, empno, row_number() OVER (ORDER BY salary) rn +FROM empsalary +ORDER BY salary, empno; + +RESET enable_seqscan; + -- cleanup DROP TABLE empsalary; |