[Commits] dbc7c35: MDEV-17017 Explain for query using derived table specified with a table
revision-id: dbc7c3562d523e194734c206c0f0e1cb78164cf0 (mariadb-10.3.7-138-gdbc7c35) parent(s): 34c7222c088ded8f1192142db935c000b2ba6b8d author: Igor Babaev committer: Igor Babaev timestamp: 2018-08-18 22:57:20 -0700 message: MDEV-17017 Explain for query using derived table specified with a table value constructor shows wrong number of rows If the specification of a derived table contained a table value constructor then the optimizer incorrectly estimated the number of rows in the derived table. This happened because the optimizer did not take into account the number of rows in the constructor. The wrong estimate could lead to choosing inefficient execution plans. --- mysql-test/main/opt_tvc.result | 30 ++++++++-------- mysql-test/main/opt_tvc.test | 2 +- mysql-test/main/range.result | 6 ++-- mysql-test/main/range.test | 4 +++ mysql-test/main/range_mrr_icp.result | 6 ++-- mysql-test/main/table_value_constr.result | 57 +++++++++++++++++++++++++++++++ mysql-test/main/table_value_constr.test | 29 ++++++++++++++++ sql/sql_tvc.h | 2 ++ sql/sql_union.cc | 2 ++ 9 files changed, 115 insertions(+), 23 deletions(-) diff --git a/mysql-test/main/opt_tvc.result b/mysql-test/main/opt_tvc.result index 0ecae5b..fdbd932 100644 --- a/mysql-test/main/opt_tvc.result +++ b/mysql-test/main/opt_tvc.result @@ -486,34 +486,32 @@ a b deallocate prepare stmt; # use inside out access from tvc rows set @@in_predicate_conversion_threshold= default; -select * from t3 where a in (1,4,10); +select * from t3 where a in (1,4); a b 1 abc 1 todd 1 sm 4 yq -10 abc -explain extended select * from t3 where a in (1,4,10); +explain extended select * from t3 where a in (1,4); id select_type table type possible_keys key key_len ref rows filtered Extra -1 SIMPLE t3 range idx idx 5 NULL 5 100.00 Using index condition +1 SIMPLE t3 range idx idx 5 NULL 4 100.00 Using index condition Warnings: -Note 1003 select `test`.`t3`.`a` AS `a`,`test`.`t3`.`b` AS `b` from `test`.`t3` where `test`.`t3`.`a` in (1,4,10) +Note 1003 select `test`.`t3`.`a` AS `a`,`test`.`t3`.`b` AS `b` from `test`.`t3` where `test`.`t3`.`a` in (1,4) set @@in_predicate_conversion_threshold= 2; -select * from t3 where a in (1,4,10); +select * from t3 where a in (1,4); a b 1 abc 1 todd 1 sm 4 yq -10 abc -explain extended select * from t3 where a in (1,4,10); +explain extended select * from t3 where a in (1,4); 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 t3 ref idx idx 5 tvc_0.1 3 100.00 2 MATERIALIZED <derived3> ALL NULL NULL NULL NULL 2 100.00 3 DERIVED NULL NULL NULL NULL NULL NULL NULL NULL No tables used Warnings: -Note 1003 /* select#1 */ select `test`.`t3`.`a` AS `a`,`test`.`t3`.`b` AS `b` from `test`.`t3` semi join ((values (1),(4),(10)) `tvc_0`) where `test`.`t3`.`a` = `tvc_0`.`1` +Note 1003 /* select#1 */ select `test`.`t3`.`a` AS `a`,`test`.`t3`.`b` AS `b` from `test`.`t3` semi join ((values (1),(4)) `tvc_0`) where `test`.`t3`.`a` = `tvc_0`.`1` # use vectors in IN predeicate set @@in_predicate_conversion_threshold= 4; select * from t1 where (a,b) in ((1,2),(3,4)); @@ -540,9 +538,9 @@ explain extended select * from t2 where (a,b) in ((1,2),(8,9)) and (a,c) in ((1,3),(8,0),(5,1)); 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 <subquery2> ALL distinct_key NULL NULL NULL 3 100.00 1 PRIMARY t2 ALL NULL NULL NULL NULL 6 100.00 Using where; Using join buffer (flat, BNL join) -2 MATERIALIZED <derived3> ALL NULL NULL NULL NULL 2 100.00 +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`.`1` and `test`.`t2`.`c` = `tvc_0`.`3` and (`tvc_0`.`1`,`test`.`t2`.`b`) in (<cache>((1,2)),<cache>((8,9))) @@ -570,7 +568,7 @@ explain extended select * from t1 where (a,b) not in ((1,2),(8,9), (5,1)); id select_type table type possible_keys key key_len ref rows filtered Extra 1 PRIMARY t1 ALL NULL NULL NULL NULL 6 100.00 Using where -2 MATERIALIZED <derived3> ALL NULL NULL NULL NULL 2 100.00 +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`.`t1`.`a` AS `a`,`test`.`t1`.`b` AS `b` from `test`.`t1` where !<expr_cache><`test`.`t1`.`a`,`test`.`t1`.`b`>(<in_optimizer>((`test`.`t1`.`a`,`test`.`t1`.`b`),(`test`.`t1`.`a`,`test`.`t1`.`b`) in ( <materialize> (/* select#2 */ select `tvc_0`.`1`,`tvc_0`.`2` from (values (1,2),(8,9),(5,1)) `tvc_0` ), <primary_index_lookup>(`test`.`t1`.`a` in <temporary table> on distinct_key where `test`.`t1`.`a` = `<subquery2>`.`1` and `test`.`t1`.`b` = `<subquery2>`.`2`)))) @@ -578,7 +576,7 @@ explain extended select * from t1 where (a,b) not in (select * from (values (1,2),(8,9), (5,1)) as tvc_0); id select_type table type possible_keys key key_len ref rows filtered Extra 1 PRIMARY t1 ALL NULL NULL NULL NULL 6 100.00 Using where -2 MATERIALIZED <derived3> ALL NULL NULL NULL NULL 2 100.00 +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`.`t1`.`a` AS `a`,`test`.`t1`.`b` AS `b` from `test`.`t1` where !<expr_cache><`test`.`t1`.`a`,`test`.`t1`.`b`>(<in_optimizer>((`test`.`t1`.`a`,`test`.`t1`.`b`),(`test`.`t1`.`a`,`test`.`t1`.`b`) in ( <materialize> (/* select#2 */ select `tvc_0`.`1`,`tvc_0`.`2` from (values (1,2),(8,9),(5,1)) `tvc_0` ), <primary_index_lookup>(`test`.`t1`.`a` in <temporary table> on distinct_key where `test`.`t1`.`a` = `<subquery2>`.`1` and `test`.`t1`.`b` = `<subquery2>`.`2`)))) @@ -592,7 +590,7 @@ explain extended select * from t1 where b < 7 and (a,b) not in ((1,2),(8,9), (5,1)); id select_type table type possible_keys key key_len ref rows filtered Extra 1 PRIMARY t1 ALL NULL NULL NULL NULL 6 100.00 Using where -2 MATERIALIZED <derived3> ALL NULL NULL NULL NULL 2 100.00 +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`.`t1`.`a` AS `a`,`test`.`t1`.`b` AS `b` from `test`.`t1` where `test`.`t1`.`b` < 7 and !<expr_cache><`test`.`t1`.`a`,`test`.`t1`.`b`>(<in_optimizer>((`test`.`t1`.`a`,`test`.`t1`.`b`),(`test`.`t1`.`a`,`test`.`t1`.`b`) in ( <materialize> (/* select#2 */ select `tvc_0`.`1`,`tvc_0`.`2` from (values (1,2),(8,9),(5,1)) `tvc_0` ), <primary_index_lookup>(`test`.`t1`.`a` in <temporary table> on distinct_key where `test`.`t1`.`a` = `<subquery2>`.`1` and `test`.`t1`.`b` = `<subquery2>`.`2`)))) @@ -608,7 +606,7 @@ explain extended select * from t2 where (a,c) not in ((1,2),(8,9), (5,1)); id select_type table type possible_keys key key_len ref rows filtered Extra 1 PRIMARY t2 ALL NULL NULL NULL NULL 6 100.00 Using where -2 MATERIALIZED <derived3> ALL NULL NULL NULL NULL 2 100.00 +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` where !<expr_cache><`test`.`t2`.`a`,`test`.`t2`.`c`>(<in_optimizer>((`test`.`t2`.`a`,`test`.`t2`.`c`),(`test`.`t2`.`a`,`test`.`t2`.`c`) in ( <materialize> (/* select#2 */ select `tvc_0`.`1`,`tvc_0`.`2` from (values (1,2),(8,9),(5,1)) `tvc_0` ), <primary_index_lookup>(`test`.`t2`.`a` in <temporary table> on distinct_key where `test`.`t2`.`a` = `<subquery2>`.`1` and `test`.`t2`.`c` = `<subquery2>`.`2`)))) @@ -632,7 +630,7 @@ i EXPLAIN EXTENDED SELECT * FROM t1 WHERE i IN (NULL, NULL, NULL, NULL, NULL); id select_type table type possible_keys key key_len ref rows filtered Extra 1 PRIMARY t1 ALL NULL NULL NULL NULL 3 100.00 -1 PRIMARY <derived3> ALL NULL NULL NULL NULL 2 100.00 Using where; FirstMatch(t1); Using join buffer (flat, BNL join) +1 PRIMARY <derived3> ALL NULL NULL NULL NULL 5 100.00 Using where; FirstMatch(t1); Using join buffer (flat, BNL join) 3 DERIVED NULL NULL NULL NULL NULL NULL NULL NULL No tables used Warnings: Note 1003 /* select#1 */ select `test`.`t1`.`i` AS `i` from `test`.`t1` semi join ((values (NULL),(NULL),(NULL),(NULL),(NULL)) `tvc_0`) where `test`.`t1`.`i` = `tvc_0`.`NULL` diff --git a/mysql-test/main/opt_tvc.test b/mysql-test/main/opt_tvc.test index d5c9a5c..2d06a0a 100644 --- a/mysql-test/main/opt_tvc.test +++ b/mysql-test/main/opt_tvc.test @@ -255,7 +255,7 @@ deallocate prepare stmt; --echo # use inside out access from tvc rows -let $query= select * from t3 where a in (1,4,10); +let $query= select * from t3 where a in (1,4); set @@in_predicate_conversion_threshold= default; eval $query; eval explain extended $query; diff --git a/mysql-test/main/range.result b/mysql-test/main/range.result index e2996b9..cbf9d5b 100644 --- a/mysql-test/main/range.result +++ b/mysql-test/main/range.result @@ -1052,6 +1052,7 @@ create table t1 (a int); insert into t1 values (0),(1),(2),(3),(4),(5),(6),(7),(8),(9); create table t2 (a int, key(a)); insert into t2 select 2*(A.a + 10*(B.a + 10*C.a)) from t1 A, t1 B, t1 C; +set in_predicate_conversion_threshold= 2000; set @a="select * from t2 force index (a) where a NOT IN(0"; select count(*) from (select @a:=concat(@a, ',', a) from t2 ) Z; count(*) @@ -1062,15 +1063,14 @@ set @b= concat("explain ", @a); prepare stmt1 from @b; execute stmt1; id select_type table type possible_keys key key_len ref rows Extra -1 PRIMARY t2 index NULL a 5 NULL 1003 Using where; Using index -2 MATERIALIZED <derived3> ALL NULL NULL NULL NULL 2 -3 DERIVED NULL NULL NULL NULL NULL NULL NULL No tables used +1 SIMPLE t2 index a a 5 NULL 1003 Using where; Using index prepare stmt1 from @a; execute stmt1; a 11 13 15 +set in_predicate_conversion_threshold= default; drop table t1, t2; CREATE TABLE t1 ( id int NOT NULL DEFAULT '0', diff --git a/mysql-test/main/range.test b/mysql-test/main/range.test index 36e0e32..43b5b18 100644 --- a/mysql-test/main/range.test +++ b/mysql-test/main/range.test @@ -870,6 +870,8 @@ insert into t1 values (0),(1),(2),(3),(4),(5),(6),(7),(8),(9); create table t2 (a int, key(a)); insert into t2 select 2*(A.a + 10*(B.a + 10*C.a)) from t1 A, t1 B, t1 C; +set in_predicate_conversion_threshold= 2000; + set @a="select * from t2 force index (a) where a NOT IN(0"; select count(*) from (select @a:=concat(@a, ',', a) from t2 ) Z; set @a=concat(@a, ')'); @@ -884,6 +886,8 @@ execute stmt1; prepare stmt1 from @a; execute stmt1; +set in_predicate_conversion_threshold= default; + drop table t1, t2; # diff --git a/mysql-test/main/range_mrr_icp.result b/mysql-test/main/range_mrr_icp.result index 629d183..483957f 100644 --- a/mysql-test/main/range_mrr_icp.result +++ b/mysql-test/main/range_mrr_icp.result @@ -1054,6 +1054,7 @@ create table t1 (a int); insert into t1 values (0),(1),(2),(3),(4),(5),(6),(7),(8),(9); create table t2 (a int, key(a)); insert into t2 select 2*(A.a + 10*(B.a + 10*C.a)) from t1 A, t1 B, t1 C; +set in_predicate_conversion_threshold= 2000; set @a="select * from t2 force index (a) where a NOT IN(0"; select count(*) from (select @a:=concat(@a, ',', a) from t2 ) Z; count(*) @@ -1064,15 +1065,14 @@ set @b= concat("explain ", @a); prepare stmt1 from @b; execute stmt1; id select_type table type possible_keys key key_len ref rows Extra -1 PRIMARY t2 index NULL a 5 NULL 1003 Using where; Using index -2 MATERIALIZED <derived3> ALL NULL NULL NULL NULL 2 -3 DERIVED NULL NULL NULL NULL NULL NULL NULL No tables used +1 SIMPLE t2 index a a 5 NULL 1003 Using where; Using index prepare stmt1 from @a; execute stmt1; a 11 13 15 +set in_predicate_conversion_threshold= default; drop table t1, t2; CREATE TABLE t1 ( id int NOT NULL DEFAULT '0', diff --git a/mysql-test/main/table_value_constr.result b/mysql-test/main/table_value_constr.result index 9e0a096..b0b0fa8 100644 --- a/mysql-test/main/table_value_constr.result +++ b/mysql-test/main/table_value_constr.result @@ -2097,3 +2097,60 @@ v # with t as (values (),()) select 1 from t; ERROR HY000: Row with no elements is not allowed in table value constructor in this context +# +# MDEV-17017: TVC in derived table +# +create table t1 (a int); +insert into t1 values (9), (3), (2); +select * from (values (7), (5), (8), (1), (3), (8), (1)) t; +7 +7 +5 +8 +1 +3 +8 +1 +explain select * from (values (7), (5), (8), (1), (3), (8), (1)) t; +id select_type table type possible_keys key key_len ref rows Extra +1 PRIMARY <derived2> ALL NULL NULL NULL NULL 7 +2 DERIVED NULL NULL NULL NULL NULL NULL NULL No tables used +select * from (values (1,11), (7,77), (3,31), (4,42)) t; +1 11 +1 11 +7 77 +3 31 +4 42 +explain select * from (values (1,11), (7,77), (3,31), (4,42)) t; +id select_type table type possible_keys key key_len ref rows Extra +1 PRIMARY <derived2> ALL NULL NULL NULL NULL 4 +2 DERIVED NULL NULL NULL NULL NULL NULL NULL No tables used +select * from (values (7), (5), (8), (1) union values (3), (8), (1)) t; +7 +7 +5 +8 +1 +3 +explain select * from (values (7), (5), (8), (1) union values (3), (8), (1)) t; +id select_type table type possible_keys key key_len ref rows Extra +1 PRIMARY <derived2> ALL NULL NULL NULL NULL 7 +2 DERIVED NULL NULL NULL NULL NULL NULL NULL No tables used +3 UNION NULL NULL NULL NULL NULL NULL NULL No tables used +NULL UNION RESULT <union2,3> ALL NULL NULL NULL NULL NULL +select * from (values (7), (5), (8), (1) union select * from t1) t; +7 +7 +5 +8 +1 +9 +3 +2 +explain select * from (values (7), (5), (8), (1) union select * from t1) t; +id select_type table type possible_keys key key_len ref rows Extra +1 PRIMARY <derived2> ALL NULL NULL NULL NULL 7 +2 DERIVED NULL NULL NULL NULL NULL NULL NULL No tables used +3 UNION t1 ALL NULL NULL NULL NULL 3 +NULL UNION RESULT <union2,3> ALL NULL NULL NULL NULL NULL +drop table t1; diff --git a/mysql-test/main/table_value_constr.test b/mysql-test/main/table_value_constr.test index eb5ea59..eb30f00 100644 --- a/mysql-test/main/table_value_constr.test +++ b/mysql-test/main/table_value_constr.test @@ -1075,3 +1075,32 @@ DELIMITER ;| --error ER_EMPTY_ROW_IN_TVC with t as (values (),()) select 1 from t; + +--echo # +--echo # MDEV-17017: TVC in derived table +--echo # + +create table t1 (a int); +insert into t1 values (9), (3), (2); + +let $q1= +select * from (values (7), (5), (8), (1), (3), (8), (1)) t; +eval $q1; +eval explain $q1; + +let $q2= +select * from (values (1,11), (7,77), (3,31), (4,42)) t; +eval $q2; +eval explain $q2; + +let $q3= +select * from (values (7), (5), (8), (1) union values (3), (8), (1)) t; +eval $q3; +eval explain $q3; + +let $q4= +select * from (values (7), (5), (8), (1) union select * from t1) t; +eval $q4; +eval explain $q4; + +drop table t1; diff --git a/sql/sql_tvc.h b/sql/sql_tvc.h index 420311c..128cc88 100644 --- a/sql/sql_tvc.h +++ b/sql/sql_tvc.h @@ -50,6 +50,8 @@ class table_value_constr : public Sql_alloc have_query_plan(QEP_NOT_PRESENT_YET), explain(0), select_options(select_options_arg) { }; + + ha_rows get_records() { return lists_of_values.elements; } bool prepare(THD *thd_arg, SELECT_LEX *sl, select_result *tmp_result, diff --git a/sql/sql_union.cc b/sql/sql_union.cc index 1203532..c8bf9bd 100644 --- a/sql/sql_union.cc +++ b/sql/sql_union.cc @@ -1321,6 +1321,8 @@ bool st_select_lex_unit::optimize() thd->lex->current_select= lex_select_save; DBUG_RETURN(TRUE); } + if (derived) + sl->increase_derived_records(sl->tvc->get_records()); continue; } thd->lex->current_select= sl;
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IgorBabaev