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Allow usage of match_orclause_to_indexcol() for joins

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This commit allows transformation of OR-clauses into SAOP's for index scans
within nested loop joins.  That required the following changes.

 1. Make match_orclause_to_indexcol() and group_similar_or_args() understand
    const-ness in the same way as match_opclause_to_indexcol().  This
    generally makes our approach more uniform.
 2. Make match_join_clauses_to_index() pass OR-clauses to
    match_clause_to_index().
 3. Also switch match_join_clauses_to_index() to use list_append_unique_ptr()
    for adding clauses to *joinorclauses.  That avoids possible duplicates
    when processing the same clauses with different indexes.  Previously such
    duplicates were elimited in match_clause_to_index(), but now
    group_similar_or_args() each time generates distinct copies of grouped
    OR clauses.

Discussion: https://postgr.es/m/CAPpHfdv%2BjtNwofg-p5z86jLYZUTt6tR17Wy00ta0dL%3DwHQN3ZA%40mail.gmail.com
Reviewed-by: Andrei Lepikhov <lepihov@gmail.com>
Reviewed-by: Alena Rybakina <a.rybakina@postgrespro.ru>
Reviewed-by: Pavel Borisov <pashkin.elfe@gmail.com>
This commit is contained in:
Alexander Korotkov
2025-02-04 23:21:49 +02:00
parent 23ef119f58
commit 627d63419e
6 changed files with 150 additions and 42 deletions
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9
src/test/regress/sql/create_index.sql
View File

@@ -781,6 +781,12 @@ EXPLAIN (COSTS OFF)
SELECT * FROM tenk1
WHERE tenthous = 1::numeric OR tenthous = 3::int4 OR tenthous = 42::numeric;
EXPLAIN (COSTS OFF)
SELECT count(*) FROM tenk1 t1
WHERE t1.thousand = 42 OR t1.thousand = (SELECT t2.tenthous FROM tenk1 t2 WHERE t2.thousand = t1.tenthous + 1 LIMIT 1);
SELECT count(*) FROM tenk1 t1
WHERE t1.thousand = 42 OR t1.thousand = (SELECT t2.tenthous FROM tenk1 t2 WHERE t2.thousand = t1.tenthous + 1 LIMIT 1);
EXPLAIN (COSTS OFF)
SELECT count(*) FROM tenk1
WHERE hundred = 42 AND (thousand = 42 OR thousand = 99);
@@ -1367,6 +1373,9 @@ CREATE STATISTICS t_a_b_stat (mcv) ON a, b FROM bitmap_split_or;
CREATE STATISTICS t_b_c_stat (mcv) ON b, c FROM bitmap_split_or;
ANALYZE bitmap_split_or;
EXPLAIN (COSTS OFF)
SELECT * FROM bitmap_split_or t1, bitmap_split_or t2
WHERE t1.a = t2.b OR t1.a = 2;
EXPLAIN (COSTS OFF)
SELECT * FROM bitmap_split_or WHERE a = 1 AND (b = 1 OR b = 2) AND c = 2;
DROP TABLE bitmap_split_or;

18
src/test/regress/sql/join.sql
View File

@@ -3016,7 +3016,6 @@ SELECT t1.a FROM skip_fetch t1 LEFT JOIN skip_fetch t2 ON t2.a = 1 WHERE t2.a IS
RESET enable_indexonlyscan;
RESET enable_seqscan;
-- Test BitmapHeapScan with a rescan releases resources correctly
SET enable_seqscan = off;
SET enable_indexscan = off;
@@ -3046,3 +3045,20 @@ SELECT 1 FROM group_tbl t1
GROUP BY s.c1, s.c2;
DROP TABLE group_tbl;
--
-- Test for a nested loop join involving index scan, transforming OR-clauses
-- to SAOP.
--
EXPLAIN (COSTS OFF)
SELECT COUNT(*) FROM tenk1 t1, tenk1 t2
WHERE t2.thousand = t1.tenthous OR t2.thousand = t1.unique1 OR t2.thousand = t1.unique2;
SELECT COUNT(*) FROM tenk1 t1, tenk1 t2
WHERE t2.thousand = t1.tenthous OR t2.thousand = t1.unique1 OR t2.thousand = t1.unique2;
EXPLAIN (COSTS OFF)
SELECT COUNT(*) FROM onek t1 LEFT JOIN tenk1 t2
ON (t2.thousand = t1.tenthous OR t2.thousand = t1.thousand);
SELECT COUNT(*) FROM onek t1 LEFT JOIN tenk1 t2
ON (t2.thousand = t1.tenthous OR t2.thousand = t1.thousand);