MDEV-20109: Optimizer ignores distinct key created for materialized...
(Backported to 10.3, addressed review input)
Sj_materialization_picker::check_qep(): fix error in cost/fanout
calculations:
- for each join prefix, add #prefix_rows / TIME_FOR_COMPARE to the cost,
like best_extension_by_limited_search does
- Remove the fanout produced by the subquery tables.
- Also take into account join condition selectivity
optimize_wo_join_buffering() (used by LooseScan and FirstMatch)
- also add #prefix_rows / TIME_FOR_COMPARE to the cost of each prefix.
- Also take into account join condition selectivity
3 MATERIALIZED <derived4> ALL NULL NULL NULL NULL 2 100.00
4 DERIVED NULL NULL NULL NULL NULL NULL NULL NULL No tables used
Warnings:
Note 1003 with tvc_0 as (/* select#2 */ select `test`.`t1`.`a` AS `a`,`test`.`t1`.`b` AS `b` from `test`.`t1` semi join ((values (1),(2)) `tvc_0`) where `test`.`t1`.`a` in (1,2))/* select#1 */ select `test`.`t1`.`a` AS `a`,`test`.`t1`.`b` AS `b` from `test`.`t1` semi join ((values (1),(2)) `tvc_0`) where `test`.`t1`.`a` = `tvc_0`.`_col_1`
Note 1003 with tvc_0 as (/* select#2 */ select `test`.`t1`.`a` AS `a`,`test`.`t1`.`b` AS `b` from `test`.`t1` semi join ((values (1),(2)) `tvc_0`) where `test`.`t1`.`a` in (1,2))/* select#1 */ select `test`.`t1`.`a` AS `a`,`test`.`t1`.`b` AS `b` from `test`.`t1` semi join ((values (1),(2)) `tvc_0`) where 1
explain extended select * from
(
select *
@ -283,12 +283,12 @@ as tvc_0
)
) as dr_table;
id select_type table type possible_keys key key_len ref rows filtered Extra
1 PRIMARY <subquery3> ALL distinct_key NULL NULL NULL 2 100.00
1 PRIMARY t1 ALL NULL NULL NULL NULL 6 100.00 Using where; Using join buffer (flat, BNL join)
2 MATERIALIZED <derived3> ALL NULL NULL NULL NULL 3 100.00
3 DERIVED NULL NULL NULL NULL NULL NULL NULL NULL No tables used
Warnings:
Note 1003 /* select#1 */ select `test`.`t2`.`a` AS `a`,`test`.`t2`.`b` AS `b`,`test`.`t2`.`c` AS `c` from `test`.`t2` semi join ((values (1,3),(8,0),(5,1)) `tvc_0`) where `test`.`t2`.`a` = `tvc_0`.`_col_1` and `test`.`t2`.`c` = `tvc_0`.`_col_2` and (`tvc_0`.`_col_1`,`test`.`t2`.`b`) in (<cache>((1,2)),<cache>((8,9)))
Note 1003 /* select#1 */ select `test`.`t2`.`a` AS `a`,`test`.`t2`.`b` AS `b`,`test`.`t2`.`c` AS `c` from `test`.`t2` semi join ((values (1,3),(8,0),(5,1)) `tvc_0`) where (`test`.`t2`.`a`,`test`.`t2`.`b`) in (<cache>((1,2)),<cache>((8,9)))
set @@in_predicate_conversion_threshold= 2;
#
# mdev-14281: conversion of NOT IN predicate into subquery predicate
2 MATERIALIZED t1 ALL varchar_key NULL NULL NULL 15 100.00 Using where
Warnings:
Note 1003 select `test`.`t2`.`varchar_nokey` AS `varchar_nokey` from `test`.`t2` semi join (`test`.`t1`) where `test`.`t1`.`varchar_nokey` = `test`.`t1`.`varchar_key` and `test`.`t2`.`varchar_nokey` = `test`.`t1`.`varchar_key` and (`test`.`t1`.`varchar_key` < 'n' xor `test`.`t1`.`pk`)
Note 1003 select `test`.`t2`.`varchar_nokey` AS `varchar_nokey` from `test`.`t2` semi join (`test`.`t1`) where `test`.`t1`.`varchar_nokey` = `test`.`t1`.`varchar_key` and (`test`.`t1`.`varchar_key` < 'n' xor `test`.`t1`.`pk`)
1 PRIMARY t1 ALL NULL NULL NULL NULL 3 100.00 Using where; Using join buffer (flat, BNL join)
1 PRIMARY t3 ALL NULL NULL NULL NULL 5 100.00 Using where; Using join buffer (flat, BNL join)
2 MATERIALIZED t4 index f2 f2 5 NULL 2 100.00 Using index
Warnings:
Note 1003 select `test`.`t1`.`f1` AS `f1`,`test`.`t1`.`f2` AS `f2`,`test`.`t2`.`f3` AS `f3`,`test`.`t3`.`f3` AS `f3` from `test`.`t1` semi join (`test`.`t4`) join `test`.`t2` join `test`.`t3` where `test`.`t4`.`f2` = `test`.`t2`.`f3` and `test`.`t3`.`f1` = `test`.`t1`.`f1` and `test`.`t1`.`f2` = `test`.`t2`.`f2`
Note 1003 select `test`.`t1`.`f1` AS `f1`,`test`.`t1`.`f2` AS `f2`,`test`.`t2`.`f3` AS `f3`,`test`.`t3`.`f3` AS `f3` from `test`.`t1` semi join (`test`.`t4`) join `test`.`t2` join `test`.`t3` where `test`.`t3`.`f1` = `test`.`t1`.`f1` and `test`.`t1`.`f2` = `test`.`t2`.`f2`
SELECT * FROM t1 NATURAL LEFT JOIN (t2, t3) WHERE t2.f3 IN (SELECT * FROM t4);
f1 f2 f3 f3
2 0 0 0
@ -2495,8 +2496,8 @@ WHERE t1.a = t2.a AND t2.a IN (SELECT b FROM t3 STRAIGHT_JOIN t4);
id select_type table type possible_keys key key_len ref rows Extra
1 PRIMARY t3 system NULL NULL NULL NULL 1
1 PRIMARY <subquery2> ALL distinct_key NULL NULL NULL 1
1 PRIMARY t1 ref a a 5 const 1 Using index
1 PRIMARY t2 ref a a 5 func 1 Using index
1 PRIMARY t2 ref a a 5 const 1 Using index
1 PRIMARY t1 ref a a 5 func 1 Using index
2 MATERIALIZED t4 ALL NULL NULL NULL NULL 0
SELECT * FROM t1, t2
WHERE t1.a = t2.a AND t2.a IN (SELECT b FROM t3 STRAIGHT_JOIN t4);
@ -2701,8 +2702,8 @@ a
19
explain select * from t3 where a in (select kp1 from t1 where kp1<20);
id select_type table type possible_keys key key_len ref rows Extra
1 PRIMARY t1 range kp1 kp1 5 NULL 48 Using where; Using index; LooseScan
1 PRIMARY t3 ALL NULL NULL NULL NULL 100 Using where; Using join buffer (flat, BNL join)
1 PRIMARY t3 ALL NULL NULL NULL NULL 100 Using where
@ -2918,8 +2919,8 @@ WHERE alias1.pk = 58 OR alias1.col_varchar_key = 'o'
);
id select_type table type possible_keys key key_len ref rows Extra
1 PRIMARY t2 ALL NULL NULL NULL NULL 2
1 PRIMARY alias1 index_merge PRIMARY,col_int_key,col_varchar_key PRIMARY,col_varchar_key 4,4 NULL 2 Using sort_union(PRIMARY,col_varchar_key); Using where
1 PRIMARY alias2 ALL col_int_key NULL NULL NULL 12 Range checked for each record (index map: 0x2); FirstMatch(t2)
1 PRIMARY alias1 index_merge PRIMARY,col_int_key,col_varchar_key PRIMARY,col_varchar_key 4,4 NULL 2 Using sort_union(PRIMARY,col_varchar_key); Using where; Start temporary
1 PRIMARY alias2 ALL col_int_key NULL NULL NULL 12 Range checked for each record (index map: 0x2); End temporary
SELECT *
FROM t2
WHERE (field1) IN (SELECT alias1.col_varchar_nokey AS field1
2 MATERIALIZED t2 ALL NULL NULL NULL NULL 2 100.00 Using where
2 MATERIALIZED t3 hash_ALL NULL #hash#$hj 5 test.t2.i2 3 100.00 Using where; Using join buffer (flat, BNLH join)
Warnings:
Note 1003 select `test`.`t1`.`i1` AS `i1` from `test`.`t1` semi join (`test`.`t2` join `test`.`t3`) where `test`.`t3`.`i3` = `test`.`t2`.`i2` and `test`.`t1`.`i1` = `test`.`t2`.`i2` and `test`.`t3`.`i3` > 0
Note 1003 select `test`.`t1`.`i1` AS `i1` from `test`.`t1` semi join (`test`.`t2` join `test`.`t3`) where `test`.`t3`.`i3` = `test`.`t2`.`i2` and `test`.`t3`.`i3` > 0
SELECT * FROM t1
WHERE i1 IN (SELECT i3 FROM t2, t3 WHERE i3 > 0 AND i3 = i2 OR 1=2);
i1
@ -1702,8 +1704,8 @@ OR
);
id select_type table type possible_keys key key_len ref rows Extra
1 PRIMARY t index PRIMARY PRIMARY 4 NULL 13 Using where; Using index
2 MATERIALIZED <subquery3> ALL distinct_key NULL NULL NULL 8
2 MATERIALIZED A ALL PRIMARY NULL NULL NULL 13 Using where; Using join buffer (flat, BNL join)
2 MATERIALIZED t1 ALL varchar_key NULL NULL NULL 15 100.00 Using where
Warnings:
Note 1003 select `test`.`t2`.`varchar_nokey` AS `varchar_nokey` from `test`.`t2` semi join (`test`.`t1`) where `test`.`t1`.`varchar_nokey` = `test`.`t1`.`varchar_key` and `test`.`t2`.`varchar_nokey` = `test`.`t1`.`varchar_key` and (`test`.`t1`.`varchar_key` < 'n' xor `test`.`t1`.`pk`)
Note 1003 select `test`.`t2`.`varchar_nokey` AS `varchar_nokey` from `test`.`t2` semi join (`test`.`t1`) where `test`.`t1`.`varchar_nokey` = `test`.`t1`.`varchar_key` and (`test`.`t1`.`varchar_key` < 'n' xor `test`.`t1`.`pk`)
@ -2932,8 +2932,8 @@ WHERE alias1.pk = 58 OR alias1.col_varchar_key = 'o'
);
id select_type table type possible_keys key key_len ref rows Extra
1 PRIMARY t2 ALL NULL NULL NULL NULL 2
1 PRIMARY alias1 index_merge PRIMARY,col_int_key,col_varchar_key PRIMARY,col_varchar_key 4,4 NULL 2 Using sort_union(PRIMARY,col_varchar_key); Using where
1 PRIMARY alias2 ALL col_int_key NULL NULL NULL 12 Range checked for each record (index map: 0x2); FirstMatch(t2)
1 PRIMARY alias1 index_merge PRIMARY,col_int_key,col_varchar_key PRIMARY,col_varchar_key 4,4 NULL 2 Using sort_union(PRIMARY,col_varchar_key); Using where; Start temporary; Using join buffer (flat, BNL join)
1 PRIMARY alias2 ALL col_int_key NULL NULL NULL 12 Range checked for each record (index map: 0x2); End temporary
SELECT *
FROM t2
WHERE (field1) IN (SELECT alias1.col_varchar_nokey AS field1
3 MATERIALIZED <derived2> ALL NULL NULL NULL NULL 2 100.00
2 DERIVED NULL NULL NULL NULL NULL NULL NULL NULL No tables used
Warnings:
Note 1003 select `test`.`t1`.`a` AS `a`,`test`.`t1`.`b` AS `b` from `test`.`t1` semi join ((values (1),(2)) `tvc_0`) where `test`.`t1`.`a` = `tvc_0`.`1`
Note 1003 select `test`.`t1`.`a` AS `a`,`test`.`t1`.`b` AS `b` from `test`.`t1` semi join ((values (1),(2)) `tvc_0`) where 1
explain extended select * from t1
where a = any (select * from (values (1),(2)) as tvc_0);
id select_type table type possible_keys key key_len ref rows filtered Extra
1 PRIMARY <subquery2> ALL distinct_key NULL NULL NULL 2 100.00
1 PRIMARY t1 ALL NULL NULL NULL NULL 6 100.00 Using where; Using join buffer (flat, BNL join)
3 MATERIALIZED <derived2> ALL NULL NULL NULL NULL 2 100.00
2 DERIVED NULL NULL NULL NULL NULL NULL NULL NULL No tables used
Warnings:
Note 1003 select "test"."t1"."a" AS "a","test"."t1"."b" AS "b" from "test"."t1" semi join ((values (1),(2)) "tvc_0") where "test"."t1"."a" = "tvc_0"."1"
Note 1003 select "test"."t1"."a" AS "a","test"."t1"."b" AS "b" from "test"."t1" semi join ((values (1),(2)) "tvc_0") where 1
explain extended select * from t1
where a = any (select * from (values (1),(2)) as tvc_0);
id select_type table type possible_keys key key_len ref rows filtered Extra
1 PRIMARY <subquery2> ALL distinct_key NULL NULL NULL 2 100.00
1 PRIMARY t1 ALL NULL NULL NULL NULL 6 100.00 Using where; Using join buffer (flat, BNL join)
NULL UNION RESULT <union2,3> ALL NULL NULL NULL NULL NULL NULL
Warnings:
Note 1003 with recursive ancestors as (/* select#2 */ select `test`.`e`.`emp_id` AS `emp_id`,`test`.`e`.`name` AS `name`,`test`.`e`.`mgr` AS `mgr`,`test`.`e`.`salary` AS `salary` from `test`.`emp` FOR SYSTEM_TIME ALL `e` where `test`.`e`.`name` = 'bill' and `test`.`e`.`row_end` > @`ts_1` and `test`.`e`.`row_start` <= @`ts_1` union /* select#3 */ select `test`.`e`.`emp_id` AS `emp_id`,`test`.`e`.`name` AS `name`,`test`.`e`.`mgr` AS `mgr`,`test`.`e`.`salary` AS `salary` from `test`.`emp` FOR SYSTEM_TIME ALL `e` join `ancestors` `a` where `a`.`emp_id` = `test`.`e`.`mgr` and `test`.`e`.`row_end` > @`ts_1` and `test`.`e`.`row_start` <= @`ts_1`)/* select#1 */ select `test`.`emp`.`name` AS `name` from `test`.`emp` FOR SYSTEM_TIME ALL semi join (`ancestors`) where `test`.`emp`.`emp_id` = `ancestors`.`emp_id` and `test`.`emp`.`row_end` = TIMESTAMP'2038-01-19 03:14:07.999999'
Note 1003 with recursive ancestors as (/* select#2 */ select `test`.`e`.`emp_id` AS `emp_id`,`test`.`e`.`name` AS `name`,`test`.`e`.`mgr` AS `mgr`,`test`.`e`.`salary` AS `salary` from `test`.`emp` FOR SYSTEM_TIME ALL `e` where `test`.`e`.`name` = 'bill' and `test`.`e`.`row_end` > @`ts_1` and `test`.`e`.`row_start` <= @`ts_1` union /* select#3 */ select `test`.`e`.`emp_id` AS `emp_id`,`test`.`e`.`name` AS `name`,`test`.`e`.`mgr` AS `mgr`,`test`.`e`.`salary` AS `salary` from `test`.`emp` FOR SYSTEM_TIME ALL `e` join `ancestors` `a` where `a`.`emp_id` = `test`.`e`.`mgr` and `test`.`e`.`row_end` > @`ts_1` and `test`.`e`.`row_start` <= @`ts_1`)/* select#1 */ select `test`.`emp`.`name` AS `name` from `test`.`emp` FOR SYSTEM_TIME ALL semi join (`ancestors`) where `test`.`emp`.`row_end` = TIMESTAMP'2038-01-19 03:14:07.999999'