diff options
| -rw-r--r-- | mysql-test/r/subselect.result | 47 | ||||
| -rw-r--r-- | mysql-test/r/subselect3.result | 2 | ||||
| -rw-r--r-- | mysql-test/t/subselect.test | 25 | ||||
| -rw-r--r-- | sql/item.h | 22 | ||||
| -rw-r--r-- | sql/sql_select.cc | 26 |
5 files changed, 101 insertions, 21 deletions
diff --git a/mysql-test/r/subselect.result b/mysql-test/r/subselect.result index d3c40ce5bd5..a99b5e5925b 100644 --- a/mysql-test/r/subselect.result +++ b/mysql-test/r/subselect.result @@ -1307,7 +1307,7 @@ id select_type table type possible_keys key key_len ref rows Extra 1 PRIMARY t2 index NULL PRIMARY 4 NULL 4 Using where; Using index 2 DEPENDENT SUBQUERY t1 unique_subquery PRIMARY PRIMARY 4 func 1 Using where Warnings: -Note 1003 select `test`.`t2`.`a` AS `a` from `test`.`t2` where <in_optimizer>(`test`.`t2`.`a`,<exists>(<primary_index_lookup>(<cache>(`test`.`t2`.`a`) in t1 on PRIMARY where (`test`.`t1`.`b` <> 30)))) +Note 1003 select `test`.`t2`.`a` AS `a` from `test`.`t2` where <in_optimizer>(`test`.`t2`.`a`,<exists>(<primary_index_lookup>(<cache>(`test`.`t2`.`a`) in t1 on PRIMARY where ((`test`.`t1`.`b` <> 30) and (<cache>(`test`.`t2`.`a`) = `test`.`t1`.`a`))))) select * from t2 where t2.a in (select t1.a from t1,t3 where t1.b=t3.a); a 2 @@ -1315,8 +1315,8 @@ a explain extended select * from t2 where t2.a in (select t1.a from t1,t3 where t1.b=t3.a); id select_type table type possible_keys key key_len ref rows Extra 1 PRIMARY t2 index NULL PRIMARY 4 NULL 4 Using where; Using index -2 DEPENDENT SUBQUERY t1 eq_ref PRIMARY PRIMARY 4 func 1 Using where -2 DEPENDENT SUBQUERY t3 eq_ref PRIMARY PRIMARY 4 test.t1.b 1 Using where; Using index +2 DEPENDENT SUBQUERY t1 eq_ref PRIMARY PRIMARY 4 func 1 +2 DEPENDENT SUBQUERY t3 eq_ref PRIMARY PRIMARY 4 test.t1.b 1 Using index Warnings: Note 1003 select `test`.`t2`.`a` AS `a` from `test`.`t2` where <in_optimizer>(`test`.`t2`.`a`,<exists>(select 1 AS `Not_used` from `test`.`t1` join `test`.`t3` where ((`test`.`t3`.`a` = `test`.`t1`.`b`) and (<cache>(`test`.`t2`.`a`) = `test`.`t1`.`a`)))) drop table t1, t2, t3; @@ -1334,9 +1334,9 @@ a explain extended select * from t2 where t2.a in (select a from t1); id select_type table type possible_keys key key_len ref rows Extra 1 PRIMARY t2 index NULL a 5 NULL 4 Using where; Using index -2 DEPENDENT SUBQUERY t1 index_subquery a a 5 func 1001 Using index +2 DEPENDENT SUBQUERY t1 index_subquery a a 5 func 1001 Using index; Using where Warnings: -Note 1003 select `test`.`t2`.`a` AS `a` from `test`.`t2` where <in_optimizer>(`test`.`t2`.`a`,<exists>(<index_lookup>(<cache>(`test`.`t2`.`a`) in t1 on a))) +Note 1003 select `test`.`t2`.`a` AS `a` from `test`.`t2` where <in_optimizer>(`test`.`t2`.`a`,<exists>(<index_lookup>(<cache>(`test`.`t2`.`a`) in t1 on a where (<cache>(`test`.`t2`.`a`) = `test`.`t1`.`a`)))) select * from t2 where t2.a in (select a from t1 where t1.b <> 30); a 2 @@ -1346,7 +1346,7 @@ id select_type table type possible_keys key key_len ref rows Extra 1 PRIMARY t2 index NULL a 5 NULL 4 Using where; Using index 2 DEPENDENT SUBQUERY t1 index_subquery a a 5 func 1001 Using index; Using where Warnings: -Note 1003 select `test`.`t2`.`a` AS `a` from `test`.`t2` where <in_optimizer>(`test`.`t2`.`a`,<exists>(<index_lookup>(<cache>(`test`.`t2`.`a`) in t1 on a where (`test`.`t1`.`b` <> 30)))) +Note 1003 select `test`.`t2`.`a` AS `a` from `test`.`t2` where <in_optimizer>(`test`.`t2`.`a`,<exists>(<index_lookup>(<cache>(`test`.`t2`.`a`) in t1 on a where ((`test`.`t1`.`b` <> 30) and (<cache>(`test`.`t2`.`a`) = `test`.`t1`.`a`))))) select * from t2 where t2.a in (select t1.a from t1,t3 where t1.b=t3.a); a 2 @@ -1373,7 +1373,7 @@ id select_type table type possible_keys key key_len ref rows Extra 1 PRIMARY t2 index NULL a 5 NULL 4 Using where; Using index 2 DEPENDENT SUBQUERY t1 index_subquery a a 5 func 1001 Using index; Using where Warnings: -Note 1003 select `test`.`t2`.`a` AS `a` from `test`.`t2` where <in_optimizer>(`test`.`t2`.`a`,<exists>(<index_lookup>(<cache>(`test`.`t2`.`a`) in t1 on a where (`test`.`t1`.`b` <> 30)))) +Note 1003 select `test`.`t2`.`a` AS `a` from `test`.`t2` where <in_optimizer>(`test`.`t2`.`a`,<exists>(<index_lookup>(<cache>(`test`.`t2`.`a`) in t1 on a where ((`test`.`t1`.`b` <> 30) and (<cache>(`test`.`t2`.`a`) = `test`.`t1`.`a`))))) drop table t1, t2, t3; create table t1 (a int, b int); create table t2 (a int, b int); @@ -1737,7 +1737,7 @@ id select_type table type possible_keys key key_len ref rows Extra 1 PRIMARY t1 ALL NULL NULL NULL NULL 12 Using where 2 DEPENDENT SUBQUERY t1 unique_subquery PRIMARY PRIMARY 4 func 1 Using index; Using where Warnings: -Note 1003 select `test`.`t1`.`id` AS `id`,`test`.`t1`.`text` AS `text` from `test`.`t1` where (not(<in_optimizer>(`test`.`t1`.`id`,<exists>(<primary_index_lookup>(<cache>(`test`.`t1`.`id`) in t1 on PRIMARY where (`test`.`t1`.`id` < 8)))))) +Note 1003 select `test`.`t1`.`id` AS `id`,`test`.`t1`.`text` AS `text` from `test`.`t1` where (not(<in_optimizer>(`test`.`t1`.`id`,<exists>(<primary_index_lookup>(<cache>(`test`.`t1`.`id`) in t1 on PRIMARY where ((`test`.`t1`.`id` < 8) and (<cache>(`test`.`t1`.`id`) = `test`.`t1`.`id`))))))) explain extended select * from t1 as tt where not exists (select id from t1 where id < 8 and (id = tt.id or id is null) having id is not null); id select_type table type possible_keys key key_len ref rows Extra 1 PRIMARY tt ALL NULL NULL NULL NULL 12 Using where @@ -4303,4 +4303,35 @@ LEFT(t1.a1,1) SELECT a2 FROM t2 WHERE t2.a2 IN (SELECT t1.a1 FROM t1,t3 WHERE t1.b1=t3.a3); a2 DROP TABLE t1, t2, t3; +CREATE TABLE t1 (a CHAR(1), b VARCHAR(10)); +INSERT INTO t1 VALUES ('a', 'aa'); +INSERT INTO t1 VALUES ('a', 'aaa'); +SELECT a,b FROM t1 WHERE b IN (SELECT a FROM t1); +a b +CREATE INDEX I1 ON t1 (a); +CREATE INDEX I2 ON t1 (b); +EXPLAIN SELECT a,b FROM t1 WHERE b IN (SELECT a FROM t1); +id select_type table type possible_keys key key_len ref rows Extra +1 PRIMARY t1 ALL NULL NULL NULL NULL 2 Using where +2 DEPENDENT SUBQUERY t1 index_subquery I1 I1 2 func 2 Using index; Using where +SELECT a,b FROM t1 WHERE b IN (SELECT a FROM t1); +a b +CREATE TABLE t2 (a VARCHAR(1), b VARCHAR(10)); +INSERT INTO t2 SELECT * FROM t1; +CREATE INDEX I1 ON t2 (a); +CREATE INDEX I2 ON t2 (b); +EXPLAIN SELECT a,b FROM t2 WHERE b IN (SELECT a FROM t2); +id select_type table type possible_keys key key_len ref rows Extra +1 PRIMARY t2 ALL NULL NULL NULL NULL 2 Using where +2 DEPENDENT SUBQUERY t2 index_subquery I1 I1 4 func 2 Using index; Using where +SELECT a,b FROM t2 WHERE b IN (SELECT a FROM t2); +a b +EXPLAIN +SELECT a,b FROM t1 WHERE b IN (SELECT a FROM t1 WHERE LENGTH(a)<500); +id select_type table type possible_keys key key_len ref rows Extra +1 PRIMARY t1 ALL NULL NULL NULL NULL 2 Using where +2 DEPENDENT SUBQUERY t1 index_subquery I1 I1 2 func 2 Using index; Using where +SELECT a,b FROM t1 WHERE b IN (SELECT a FROM t1 WHERE LENGTH(a)<500); +a b +DROP TABLE t1,t2; End of 5.0 tests. diff --git a/mysql-test/r/subselect3.result b/mysql-test/r/subselect3.result index 098dacc8189..bdf00e4c307 100644 --- a/mysql-test/r/subselect3.result +++ b/mysql-test/r/subselect3.result @@ -757,6 +757,6 @@ a EXPLAIN SELECT a FROM t1 WHERE a NOT IN (SELECT a FROM t2); id select_type table type possible_keys key key_len ref rows Extra 1 PRIMARY t1 ALL NULL NULL NULL NULL 4 Using where -2 DEPENDENT SUBQUERY t2 unique_subquery PRIMARY PRIMARY 4 func 1 Using index +2 DEPENDENT SUBQUERY t2 unique_subquery PRIMARY PRIMARY 4 func 1 Using index; Using where DROP TABLE t1; End of 5.0 tests diff --git a/mysql-test/t/subselect.test b/mysql-test/t/subselect.test index ba6abbacf50..64b390e413d 100644 --- a/mysql-test/t/subselect.test +++ b/mysql-test/t/subselect.test @@ -3140,4 +3140,29 @@ SELECT LEFT(t1.a1,1) FROM t1,t3 WHERE t1.b1=t3.a3; SELECT a2 FROM t2 WHERE t2.a2 IN (SELECT t1.a1 FROM t1,t3 WHERE t1.b1=t3.a3); DROP TABLE t1, t2, t3; +# +# Bug #30788: Inconsistent retrieval of char/varchar +# + +CREATE TABLE t1 (a CHAR(1), b VARCHAR(10)); +INSERT INTO t1 VALUES ('a', 'aa'); +INSERT INTO t1 VALUES ('a', 'aaa'); +SELECT a,b FROM t1 WHERE b IN (SELECT a FROM t1); +CREATE INDEX I1 ON t1 (a); +CREATE INDEX I2 ON t1 (b); +EXPLAIN SELECT a,b FROM t1 WHERE b IN (SELECT a FROM t1); +SELECT a,b FROM t1 WHERE b IN (SELECT a FROM t1); + +CREATE TABLE t2 (a VARCHAR(1), b VARCHAR(10)); +INSERT INTO t2 SELECT * FROM t1; +CREATE INDEX I1 ON t2 (a); +CREATE INDEX I2 ON t2 (b); +EXPLAIN SELECT a,b FROM t2 WHERE b IN (SELECT a FROM t2); +SELECT a,b FROM t2 WHERE b IN (SELECT a FROM t2); +EXPLAIN +SELECT a,b FROM t1 WHERE b IN (SELECT a FROM t1 WHERE LENGTH(a)<500); +SELECT a,b FROM t1 WHERE b IN (SELECT a FROM t1 WHERE LENGTH(a)<500); + +DROP TABLE t1,t2; + --echo End of 5.0 tests. diff --git a/sql/item.h b/sql/item.h index a1135c2c725..5046e0ceb93 100644 --- a/sql/item.h +++ b/sql/item.h @@ -2452,8 +2452,18 @@ class Item_cache: public Item protected: Item *example; table_map used_table_map; + /* + Field that this object will get value from. This is set/used by + index-based subquery engines to detect and remove the equality injected + by IN->EXISTS transformation. + For all other uses of Item_cache, cached_field doesn't matter. + */ + Field *cached_field; public: - Item_cache(): example(0), used_table_map(0) {fixed= 1; null_value= 1;} + Item_cache(): example(0), used_table_map(0), cached_field(0) + { + fixed= 1; null_value= 1; + } void set_used_tables(table_map map) { used_table_map= map; } @@ -2465,6 +2475,8 @@ public: decimals= item->decimals; collation.set(item->collation); unsigned_flag= item->unsigned_flag; + if (item->type() == FIELD_ITEM) + cached_field= ((Item_field *)item)->field; return 0; }; virtual void store(Item *)= 0; @@ -2475,6 +2487,14 @@ public: // to prevent drop fixed flag (no need parent cleanup call) void cleanup() {} void print(String *str); + bool eq_def(Field *field) + { + return cached_field ? cached_field->eq_def (field) : FALSE; + } + bool eq(const Item *item, bool binary_cmp) const + { + return this == item; + } }; diff --git a/sql/sql_select.cc b/sql/sql_select.cc index e25d0d78c87..ea47477c59c 100644 --- a/sql/sql_select.cc +++ b/sql/sql_select.cc @@ -217,6 +217,7 @@ static void select_describe(JOIN *join, bool need_tmp_table,bool need_order, bool distinct, const char *message=NullS); static Item *remove_additional_cond(Item* conds); static void add_group_and_distinct_keys(JOIN *join, JOIN_TAB *join_tab); +static bool test_if_ref(Item_field *left_item,Item *right_item); /* @@ -681,9 +682,6 @@ err: without "checking NULL", remove the predicates that were pushed down into the subquery. - We can remove the equalities that will be guaranteed to be true by the - fact that subquery engine will be using index lookup. - If the subquery compares scalar values, we can remove the condition that was wrapped into trig_cond (it will be checked when needed by the subquery engine) @@ -693,6 +691,12 @@ err: and non-NULL values, we'll do a full table scan and will rely on the equalities corresponding to non-NULL parts of left tuple to filter out non-matching records. + + TODO: We can remove the equalities that will be guaranteed to be true by the + fact that subquery engine will be using index lookup. This must be done only + for cases where there are no conversion errors of significance, e.g. 257 + that is searched in a byte. But this requires homogenization of the return + codes of all Field*::store() methods. */ void JOIN::remove_subq_pushed_predicates(Item **where) @@ -700,17 +704,13 @@ void JOIN::remove_subq_pushed_predicates(Item **where) if (conds->type() == Item::FUNC_ITEM && ((Item_func *)this->conds)->functype() == Item_func::EQ_FUNC && ((Item_func *)conds)->arguments()[0]->type() == Item::REF_ITEM && - ((Item_func *)conds)->arguments()[1]->type() == Item::FIELD_ITEM) + ((Item_func *)conds)->arguments()[1]->type() == Item::FIELD_ITEM && + test_if_ref ((Item_field *)((Item_func *)conds)->arguments()[1], + ((Item_func *)conds)->arguments()[0])) { *where= 0; return; } - if (conds->type() == Item::COND_ITEM && - ((class Item_func *)this->conds)->functype() == - Item_func::COND_AND_FUNC) - { - *where= remove_additional_cond(conds); - } } @@ -1236,7 +1236,7 @@ JOIN::optimize() { if (!having) { - Item *where= 0; + Item *where= conds; if (join_tab[0].type == JT_EQ_REF && join_tab[0].ref.items[0]->name == in_left_expr_name) { @@ -11892,8 +11892,12 @@ static bool test_if_ref(Item_field *left_item,Item *right_item) Item *ref_item=part_of_refkey(field->table,field); if (ref_item && ref_item->eq(right_item,1)) { + right_item= right_item->real_item(); if (right_item->type() == Item::FIELD_ITEM) return (field->eq_def(((Item_field *) right_item)->field)); + /* remove equalities injected by IN->EXISTS transformation */ + else if (right_item->type() == Item::CACHE_ITEM) + return ((Item_cache *)right_item)->eq_def (field); if (right_item->const_item() && !(right_item->is_null())) { /* |