On 10/7/2023 15:38, Alena Rybakina wrote:
I agreed with the changes. Thank you for your work.
I updated patch and added you to the authors.
I specified Ranier Vilela as a reviewer.
This patch looks much better than earlier. But it definitely needs some
covering with tests. As a first simple approximation, here you can see
the result of regression tests, where the transformation limit is set to
0. See in the attachment some test changes induced by these diffs.
Also, I see some impact of the transformation to other queries:
create_view.out:
(NOT x > z) ----> (x <= z)
inherit.out:
(((a)::text = 'ab'::text) OR ((a)::text = ANY ('{NULL,cd}'::text[])))
to
(((a)::text = ANY ('{NULL,cd}'::text[])) OR ((a)::text = 'ab'::text))
Transformations, mentioned above, are correct, of course. But it can be
a sign of possible unstable behavior.
--
regards,
Andrey Lepikhov
Postgres Professional
diff --git a/src/backend/parser/parse_expr.c b/src/backend/parser/parse_expr.c
index 0ddcb880ef..3d9b385c1f 100644
--- a/src/backend/parser/parse_expr.c
+++ b/src/backend/parser/parse_expr.c
@@ -43,6 +43,7 @@
/* GUC parameters */
bool Transform_null_equals = false;
+int or_transform_limit = 500;
static Node *transformExprRecurse(ParseState *pstate, Node *expr);
@@ -104,8 +105,6 @@ typedef struct OrClauseGroupEntry
Expr *expr;
} OrClauseGroupEntry;
-static int const_transform_or_limit = 500;
-
static Node *
transformBoolExprOr(ParseState *pstate, BoolExpr *expr_orig)
{
@@ -115,7 +114,7 @@ transformBoolExprOr(ParseState *pstate, BoolExpr *expr_orig)
/* If this is not an 'OR' expression, skip the transformation */
if (expr_orig->boolop != OR_EXPR ||
- list_length(expr_orig->args) < const_transform_or_limit)
+ list_length(expr_orig->args) < or_transform_limit)
return transformBoolExpr(pstate, (BoolExpr *) expr_orig);
foreach(lc, expr_orig->args)
diff --git a/src/backend/utils/misc/guc_tables.c
b/src/backend/utils/misc/guc_tables.c
index c14456060c..c7ac73ebe0 100644
--- a/src/backend/utils/misc/guc_tables.c
+++ b/src/backend/utils/misc/guc_tables.c
@@ -2046,6 +2046,16 @@ struct config_int ConfigureNamesInt[] =
100, 1, MAX_STATISTICS_TARGET,
NULL, NULL, NULL
},
+ {
+ {"or_transform_limit", PGC_USERSET, QUERY_TUNING_OTHER,
+ gettext_noop("Transform a sequence of OR clauses to an
IN expression."),
+ gettext_noop("The planner will replace clauses like
'x=c1 OR x=c2 .."
+ "to the clause 'x IN
(c1,c2,...)'")
+ },
+ &or_transform_limit,
+ 500, 0, INT_MAX,
+ NULL, NULL, NULL
+ },
{
{"from_collapse_limit", PGC_USERSET, QUERY_TUNING_OTHER,
gettext_noop("Sets the FROM-list size beyond which
subqueries "
diff --git a/src/include/parser/parse_expr.h b/src/include/parser/parse_expr.h
index 7d38ca75f7..891e6a462b 100644
--- a/src/include/parser/parse_expr.h
+++ b/src/include/parser/parse_expr.h
@@ -17,6 +17,7 @@
/* GUC parameters */
extern PGDLLIMPORT bool Transform_null_equals;
+extern PGDLLIMPORT int or_transform_limit;
extern Node *transformExpr(ParseState *pstate, Node *expr, ParseExprKind
exprKind);
diff --git a/src/test/regress/expected/create_index.out
b/src/test/regress/expected/create_index.out
index acfd9d1f4f..60e053d217 100644
--- a/src/test/regress/expected/create_index.out
+++ b/src/test/regress/expected/create_index.out
@@ -1883,6 +1883,46 @@ SELECT count(*) FROM tenk1
10
(1 row)
+SET or_transform_limit = 0;
+EXPLAIN (COSTS OFF)
+SELECT * FROM tenk1
+ WHERE thousand = 42 AND (tenthous = 1 OR tenthous = 3 OR tenthous = 42);
+ QUERY PLAN
+------------------------------------------------------------------------------
+ Index Scan using tenk1_thous_tenthous on tenk1
+ Index Cond: ((thousand = 42) AND (tenthous = ANY ('{1,3,42}'::integer[])))
+(2 rows)
+
+SELECT * FROM tenk1
+ WHERE thousand = 42 AND (tenthous = 1 OR tenthous = 3 OR tenthous = 42);
+ unique1 | unique2 | two | four | ten | twenty | hundred | thousand |
twothousand | fivethous | tenthous | odd | even | stringu1 | stringu2 | string4
+---------+---------+-----+------+-----+--------+---------+----------+-------------+-----------+----------+-----+------+----------+----------+---------
+ 42 | 5530 | 0 | 2 | 2 | 2 | 42 | 42 |
42 | 42 | 42 | 84 | 85 | QBAAAA | SEIAAA | OOOOxx
+(1 row)
+
+EXPLAIN (COSTS OFF)
+SELECT count(*) FROM tenk1
+ WHERE hundred = 42 AND (thousand = 42 OR thousand = 99);
+ QUERY PLAN
+------------------------------------------------------------------------------------
+ Aggregate
+ -> Bitmap Heap Scan on tenk1
+ Recheck Cond: ((hundred = 42) AND (thousand = ANY
('{42,99}'::integer[])))
+ -> BitmapAnd
+ -> Bitmap Index Scan on tenk1_hundred
+ Index Cond: (hundred = 42)
+ -> Bitmap Index Scan on tenk1_thous_tenthous
+ Index Cond: (thousand = ANY ('{42,99}'::integer[]))
+(8 rows)
+
+SELECT count(*) FROM tenk1
+ WHERE hundred = 42 AND (thousand = 42 OR thousand = 99);
+ count
+-------
+ 10
+(1 row)
+
+RESET or_transform_limit;
--
-- Check behavior with duplicate index column contents
--
diff --git a/src/test/regress/expected/guc.out
b/src/test/regress/expected/guc.out
index 127c953297..c052b113ee 100644
--- a/src/test/regress/expected/guc.out
+++ b/src/test/regress/expected/guc.out
@@ -861,7 +861,8 @@ SELECT name FROM tab_settings_flags
name
---------------------------
default_statistics_target
-(1 row)
+ or_transform_limit
+(2 rows)
-- Runtime-computed GUCs should be part of the preset category.
SELECT name FROM tab_settings_flags
diff --git a/src/test/regress/expected/join.out
b/src/test/regress/expected/join.out
index 9b8638f286..fbe711e0ee 100644
--- a/src/test/regress/expected/join.out
+++ b/src/test/regress/expected/join.out
@@ -4207,6 +4207,33 @@ select * from tenk1 a join tenk1 b on
Index Cond: (unique2 = 7)
(19 rows)
+SET or_transform_limit = 0;
+explain (costs off)
+select * from tenk1 a join tenk1 b on
+ (a.unique1 = 1 and b.unique1 = 2) or
+ ((a.unique2 = 3 or a.unique2 = 7) and b.hundred = 4);
+ QUERY PLAN
+------------------------------------------------------------------------------------------------------------------------
+ Nested Loop
+ Join Filter: (((a.unique1 = 1) AND (b.unique1 = 2)) OR ((a.unique2 = ANY
('{3,7}'::integer[])) AND (b.hundred = 4)))
+ -> Bitmap Heap Scan on tenk1 b
+ Recheck Cond: ((unique1 = 2) OR (hundred = 4))
+ -> BitmapOr
+ -> Bitmap Index Scan on tenk1_unique1
+ Index Cond: (unique1 = 2)
+ -> Bitmap Index Scan on tenk1_hundred
+ Index Cond: (hundred = 4)
+ -> Materialize
+ -> Bitmap Heap Scan on tenk1 a
+ Recheck Cond: ((unique1 = 1) OR (unique2 = ANY
('{3,7}'::integer[])))
+ -> BitmapOr
+ -> Bitmap Index Scan on tenk1_unique1
+ Index Cond: (unique1 = 1)
+ -> Bitmap Index Scan on tenk1_unique2
+ Index Cond: (unique2 = ANY ('{3,7}'::integer[]))
+(17 rows)
+
+RESET or_transform_limit;
--
-- test placement of movable quals in a parameterized join tree
--
diff --git a/src/test/regress/expected/partition_prune.out
b/src/test/regress/expected/partition_prune.out
index 2abf759385..5eb94d2821 100644
--- a/src/test/regress/expected/partition_prune.out
+++ b/src/test/regress/expected/partition_prune.out
@@ -101,6 +101,28 @@ explain (costs off) select * from lp where a is not null
and (a = 'a' or a = 'c'
Filter: ((a IS NOT NULL) AND ((a = 'a'::bpchar) OR (a = 'c'::bpchar)))
(5 rows)
+SET or_transform_limit = 0;
+explain (costs off) select * from lp where a = 'a' or a = 'c';
+ QUERY PLAN
+-----------------------------------------------
+ Append
+ -> Seq Scan on lp_ad lp_1
+ Filter: (a = ANY ('{a,c}'::bpchar[]))
+ -> Seq Scan on lp_bc lp_2
+ Filter: (a = ANY ('{a,c}'::bpchar[]))
+(5 rows)
+
+explain (costs off) select * from lp where a is not null and (a = 'a' or a =
'c');
+ QUERY PLAN
+---------------------------------------------------------------------
+ Append
+ -> Seq Scan on lp_ad lp_1
+ Filter: ((a IS NOT NULL) AND (a = ANY ('{a,c}'::bpchar[])))
+ -> Seq Scan on lp_bc lp_2
+ Filter: ((a IS NOT NULL) AND (a = ANY ('{a,c}'::bpchar[])))
+(5 rows)
+
+RESET or_transform_limit;
explain (costs off) select * from lp where a <> 'g';
QUERY PLAN
------------------------------------
@@ -671,6 +693,163 @@ explain (costs off) select * from rlp where (a = 1 and a
= 3) or (a > 1 and a =
Filter: (((a = 1) AND (a = 3)) OR ((a > 1) AND (a = 15)))
(11 rows)
+SET or_transform_limit = 0;
+explain (costs off) select * from rlp where a = 1 or a = 7;
+ QUERY PLAN
+------------------------------------------
+ Seq Scan on rlp2 rlp
+ Filter: (a = ANY ('{1,7}'::integer[]))
+(2 rows)
+
+explain (costs off) select * from rlp where a = 1 or b = 'ab';
+ QUERY PLAN
+-------------------------------------------------------
+ Append
+ -> Seq Scan on rlp1 rlp_1
+ Filter: ((a = 1) OR ((b)::text = 'ab'::text))
+ -> Seq Scan on rlp2 rlp_2
+ Filter: ((a = 1) OR ((b)::text = 'ab'::text))
+ -> Seq Scan on rlp3abcd rlp_3
+ Filter: ((a = 1) OR ((b)::text = 'ab'::text))
+ -> Seq Scan on rlp4_1 rlp_4
+ Filter: ((a = 1) OR ((b)::text = 'ab'::text))
+ -> Seq Scan on rlp4_2 rlp_5
+ Filter: ((a = 1) OR ((b)::text = 'ab'::text))
+ -> Seq Scan on rlp4_default rlp_6
+ Filter: ((a = 1) OR ((b)::text = 'ab'::text))
+ -> Seq Scan on rlp5_1 rlp_7
+ Filter: ((a = 1) OR ((b)::text = 'ab'::text))
+ -> Seq Scan on rlp5_default rlp_8
+ Filter: ((a = 1) OR ((b)::text = 'ab'::text))
+ -> Seq Scan on rlp_default_10 rlp_9
+ Filter: ((a = 1) OR ((b)::text = 'ab'::text))
+ -> Seq Scan on rlp_default_30 rlp_10
+ Filter: ((a = 1) OR ((b)::text = 'ab'::text))
+ -> Seq Scan on rlp_default_null rlp_11
+ Filter: ((a = 1) OR ((b)::text = 'ab'::text))
+ -> Seq Scan on rlp_default_default rlp_12
+ Filter: ((a = 1) OR ((b)::text = 'ab'::text))
+(25 rows)
+
+explain (costs off) select * from rlp where a > 20 and a < 27;
+ QUERY PLAN
+-----------------------------------------
+ Append
+ -> Seq Scan on rlp4_1 rlp_1
+ Filter: ((a > 20) AND (a < 27))
+ -> Seq Scan on rlp4_2 rlp_2
+ Filter: ((a > 20) AND (a < 27))
+(5 rows)
+
+explain (costs off) select * from rlp where a = 29;
+ QUERY PLAN
+------------------------------
+ Seq Scan on rlp4_default rlp
+ Filter: (a = 29)
+(2 rows)
+
+explain (costs off) select * from rlp where a >= 29;
+ QUERY PLAN
+---------------------------------------------
+ Append
+ -> Seq Scan on rlp4_default rlp_1
+ Filter: (a >= 29)
+ -> Seq Scan on rlp5_1 rlp_2
+ Filter: (a >= 29)
+ -> Seq Scan on rlp5_default rlp_3
+ Filter: (a >= 29)
+ -> Seq Scan on rlp_default_30 rlp_4
+ Filter: (a >= 29)
+ -> Seq Scan on rlp_default_default rlp_5
+ Filter: (a >= 29)
+(11 rows)
+
+explain (costs off) select * from rlp where a < 1 or (a > 20 and a < 25);
+ QUERY PLAN
+------------------------------------------------------
+ Append
+ -> Seq Scan on rlp1 rlp_1
+ Filter: ((a < 1) OR ((a > 20) AND (a < 25)))
+ -> Seq Scan on rlp4_1 rlp_2
+ Filter: ((a < 1) OR ((a > 20) AND (a < 25)))
+(5 rows)
+
+explain (costs off) select * from rlp where a = 20 or a = 40;
+ QUERY PLAN
+--------------------------------------------------
+ Append
+ -> Seq Scan on rlp4_1 rlp_1
+ Filter: (a = ANY ('{20,40}'::integer[]))
+ -> Seq Scan on rlp5_default rlp_2
+ Filter: (a = ANY ('{20,40}'::integer[]))
+(5 rows)
+
+explain (costs off) select * from rlp3 where a = 20; /* empty */
+ QUERY PLAN
+--------------------------
+ Result
+ One-Time Filter: false
+(2 rows)
+
+explain (costs off) select * from rlp where a > 1 and a = 10; /* only default
*/
+ QUERY PLAN
+----------------------------------
+ Seq Scan on rlp_default_10 rlp
+ Filter: ((a > 1) AND (a = 10))
+(2 rows)
+
+explain (costs off) select * from rlp where a > 1 and a >=15; /* rlp3
onwards, including default */
+ QUERY PLAN
+----------------------------------------------
+ Append
+ -> Seq Scan on rlp3abcd rlp_1
+ Filter: ((a > 1) AND (a >= 15))
+ -> Seq Scan on rlp3efgh rlp_2
+ Filter: ((a > 1) AND (a >= 15))
+ -> Seq Scan on rlp3nullxy rlp_3
+ Filter: ((a > 1) AND (a >= 15))
+ -> Seq Scan on rlp3_default rlp_4
+ Filter: ((a > 1) AND (a >= 15))
+ -> Seq Scan on rlp4_1 rlp_5
+ Filter: ((a > 1) AND (a >= 15))
+ -> Seq Scan on rlp4_2 rlp_6
+ Filter: ((a > 1) AND (a >= 15))
+ -> Seq Scan on rlp4_default rlp_7
+ Filter: ((a > 1) AND (a >= 15))
+ -> Seq Scan on rlp5_1 rlp_8
+ Filter: ((a > 1) AND (a >= 15))
+ -> Seq Scan on rlp5_default rlp_9
+ Filter: ((a > 1) AND (a >= 15))
+ -> Seq Scan on rlp_default_30 rlp_10
+ Filter: ((a > 1) AND (a >= 15))
+ -> Seq Scan on rlp_default_default rlp_11
+ Filter: ((a > 1) AND (a >= 15))
+(23 rows)
+
+explain (costs off) select * from rlp where a = 1 and a = 3; /* empty */
+ QUERY PLAN
+--------------------------
+ Result
+ One-Time Filter: false
+(2 rows)
+
+explain (costs off) select * from rlp where (a = 1 and a = 3) or (a > 1 and a
= 15);
+ QUERY PLAN
+-------------------------------------------------------------------
+ Append
+ -> Seq Scan on rlp2 rlp_1
+ Filter: (((a = 1) AND (a = 3)) OR ((a > 1) AND (a = 15)))
+ -> Seq Scan on rlp3abcd rlp_2
+ Filter: (((a = 1) AND (a = 3)) OR ((a > 1) AND (a = 15)))
+ -> Seq Scan on rlp3efgh rlp_3
+ Filter: (((a = 1) AND (a = 3)) OR ((a > 1) AND (a = 15)))
+ -> Seq Scan on rlp3nullxy rlp_4
+ Filter: (((a = 1) AND (a = 3)) OR ((a > 1) AND (a = 15)))
+ -> Seq Scan on rlp3_default rlp_5
+ Filter: (((a = 1) AND (a = 3)) OR ((a > 1) AND (a = 15)))
+(11 rows)
+
+RESET or_transform_limit;
-- multi-column keys
create table mc3p (a int, b int, c int) partition by range (a, abs(b), c);
create table mc3p_default partition of mc3p default;
diff --git a/src/test/regress/expected/tidscan.out
b/src/test/regress/expected/tidscan.out
index f133b5a4ac..a2949d3d69 100644
--- a/src/test/regress/expected/tidscan.out
+++ b/src/test/regress/expected/tidscan.out
@@ -56,6 +56,23 @@ SELECT ctid, * FROM tidscan WHERE ctid = '(0,2)' OR '(0,1)'
= ctid;
(0,2) | 2
(2 rows)
+SET or_transform_limit = 0;
+EXPLAIN (COSTS OFF)
+SELECT ctid, * FROM tidscan WHERE ctid = '(0,2)' OR '(0,1)' = ctid;
+ QUERY PLAN
+-------------------------------------------------------
+ Tid Scan on tidscan
+ TID Cond: (ctid = ANY ('{"(0,2)","(0,1)"}'::tid[]))
+(2 rows)
+
+SELECT ctid, * FROM tidscan WHERE ctid = '(0,2)' OR '(0,1)' = ctid;
+ ctid | id
+-------+----
+ (0,1) | 1
+ (0,2) | 2
+(2 rows)
+
+RESET or_transform_limit;
-- ctid = ScalarArrayOp - implemented as tidscan
EXPLAIN (COSTS OFF)
SELECT ctid, * FROM tidscan WHERE ctid = ANY(ARRAY['(0,1)', '(0,2)']::tid[]);
diff --git a/src/test/regress/sql/create_index.sql
b/src/test/regress/sql/create_index.sql
index d49ce9f300..0d33c0b61e 100644
--- a/src/test/regress/sql/create_index.sql
+++ b/src/test/regress/sql/create_index.sql
@@ -737,6 +737,20 @@ SELECT count(*) FROM tenk1
SELECT count(*) FROM tenk1
WHERE hundred = 42 AND (thousand = 42 OR thousand = 99);
+SET or_transform_limit = 0;
+EXPLAIN (COSTS OFF)
+SELECT * FROM tenk1
+ WHERE thousand = 42 AND (tenthous = 1 OR tenthous = 3 OR tenthous = 42);
+SELECT * FROM tenk1
+ WHERE thousand = 42 AND (tenthous = 1 OR tenthous = 3 OR tenthous = 42);
+
+EXPLAIN (COSTS OFF)
+SELECT count(*) FROM tenk1
+ WHERE hundred = 42 AND (thousand = 42 OR thousand = 99);
+SELECT count(*) FROM tenk1
+ WHERE hundred = 42 AND (thousand = 42 OR thousand = 99);
+RESET or_transform_limit;
+
--
-- Check behavior with duplicate index column contents
--
diff --git a/src/test/regress/sql/join.sql b/src/test/regress/sql/join.sql
index 3e5032b04d..3b717400d9 100644
--- a/src/test/regress/sql/join.sql
+++ b/src/test/regress/sql/join.sql
@@ -1396,6 +1396,12 @@ explain (costs off)
select * from tenk1 a join tenk1 b on
(a.unique1 = 1 and b.unique1 = 2) or
((a.unique2 = 3 or a.unique2 = 7) and b.hundred = 4);
+SET or_transform_limit = 0;
+explain (costs off)
+select * from tenk1 a join tenk1 b on
+ (a.unique1 = 1 and b.unique1 = 2) or
+ ((a.unique2 = 3 or a.unique2 = 7) and b.hundred = 4);
+RESET or_transform_limit;
--
-- test placement of movable quals in a parameterized join tree
diff --git a/src/test/regress/sql/partition_prune.sql
b/src/test/regress/sql/partition_prune.sql
index d1c60b8fe9..77f3e6c3b9 100644
--- a/src/test/regress/sql/partition_prune.sql
+++ b/src/test/regress/sql/partition_prune.sql
@@ -21,6 +21,12 @@ explain (costs off) select * from lp where a is not null;
explain (costs off) select * from lp where a is null;
explain (costs off) select * from lp where a = 'a' or a = 'c';
explain (costs off) select * from lp where a is not null and (a = 'a' or a =
'c');
+
+SET or_transform_limit = 0;
+explain (costs off) select * from lp where a = 'a' or a = 'c';
+explain (costs off) select * from lp where a is not null and (a = 'a' or a =
'c');
+RESET or_transform_limit;
+
explain (costs off) select * from lp where a <> 'g';
explain (costs off) select * from lp where a <> 'a' and a <> 'd';
explain (costs off) select * from lp where a not in ('a', 'd');
@@ -99,6 +105,22 @@ explain (costs off) select * from rlp where a > 1 and a
>=15; /* rlp3 onwards, i
explain (costs off) select * from rlp where a = 1 and a = 3; /* empty */
explain (costs off) select * from rlp where (a = 1 and a = 3) or (a > 1 and a
= 15);
+
+SET or_transform_limit = 0;
+explain (costs off) select * from rlp where a = 1 or a = 7;
+explain (costs off) select * from rlp where a = 1 or b = 'ab';
+explain (costs off) select * from rlp where a > 20 and a < 27;
+explain (costs off) select * from rlp where a = 29;
+explain (costs off) select * from rlp where a >= 29;
+explain (costs off) select * from rlp where a < 1 or (a > 20 and a < 25);
+explain (costs off) select * from rlp where a = 20 or a = 40;
+explain (costs off) select * from rlp3 where a = 20; /* empty */
+explain (costs off) select * from rlp where a > 1 and a = 10; /* only default
*/
+explain (costs off) select * from rlp where a > 1 and a >=15; /* rlp3
onwards, including default */
+explain (costs off) select * from rlp where a = 1 and a = 3; /* empty */
+explain (costs off) select * from rlp where (a = 1 and a = 3) or (a > 1 and a
= 15);
+RESET or_transform_limit;
+
-- multi-column keys
create table mc3p (a int, b int, c int) partition by range (a, abs(b), c);
create table mc3p_default partition of mc3p default;
diff --git a/src/test/regress/sql/tidscan.sql b/src/test/regress/sql/tidscan.sql
index 313e0fb9b6..634bf08e5f 100644
--- a/src/test/regress/sql/tidscan.sql
+++ b/src/test/regress/sql/tidscan.sql
@@ -22,6 +22,12 @@ EXPLAIN (COSTS OFF)
SELECT ctid, * FROM tidscan WHERE ctid = '(0,2)' OR '(0,1)' = ctid;
SELECT ctid, * FROM tidscan WHERE ctid = '(0,2)' OR '(0,1)' = ctid;
+SET or_transform_limit = 0;
+EXPLAIN (COSTS OFF)
+SELECT ctid, * FROM tidscan WHERE ctid = '(0,2)' OR '(0,1)' = ctid;
+SELECT ctid, * FROM tidscan WHERE ctid = '(0,2)' OR '(0,1)' = ctid;
+RESET or_transform_limit;
+
-- ctid = ScalarArrayOp - implemented as tidscan
EXPLAIN (COSTS OFF)
SELECT ctid, * FROM tidscan WHERE ctid = ANY(ARRAY['(0,1)', '(0,2)']::tid[]);
