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MWL#17: Table elimination

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- More test coverage
- Remove unused code
This commit is contained in:
Sergey Petrunya
2009-08-25 13:38:22 +03:00
parent 9400700b99
commit de41681afa
3 changed files with 14 additions and 12 deletions
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11
mysql-test/r/table_elim.result
View File

@ -314,8 +314,8 @@ create table t1 (a int, b int, c int, d int);
insert into t1 values (0,0,0,0),(1,1,1,1),(2,2,2,2),(3,3,3,3);
create table t2 (pk int primary key, b int)
as select a as pk, a as b from t1 where a in (1,2);
create table t3 (pk int primary key, b int)
as select a as pk, a as b from t1 where a in (1,3);
create table t3 (pk1 int, pk2 int, b int, unique(pk1,pk2));
insert into t3 select a as pk1, a as pk2, a as b from t1 where a in (1,3);
explain select t1.a from t1 left join t2 on t2.pk=t1.a and t2.b<t1.b;
id select_type table type possible_keys key key_len ref rows Extra
1 SIMPLE t1 ALL NULL NULL NULL NULL 4
@ -344,4 +344,11 @@ id select_type table type possible_keys key key_len ref rows Extra
explain select t1.a from t1 left join t2 on t2.pk in (t1.a);
id select_type table type possible_keys key key_len ref rows Extra
1 SIMPLE t1 ALL NULL NULL NULL NULL 4
explain select t1.a from t1 left join t2 on TRUE;
id select_type table type possible_keys key key_len ref rows Extra
1 SIMPLE t1 ALL NULL NULL NULL NULL 4
1 SIMPLE t2 index NULL PRIMARY 4 NULL 2 Using index
explain select t1.a from t1 left join t3 on t3.pk1=t1.a and t3.pk2 IS NULL;
id select_type table type possible_keys key key_len ref rows Extra
1 SIMPLE t1 ALL NULL NULL NULL NULL 4
drop table t1,t2,t3;

2
mysql-test/t/table_elim.test
View File

@ -274,5 +274,7 @@ explain select t1.a from t1 left join t2 on t2.pk in (t1.a);
explain select t1.a from t1 left join t2 on TRUE;
explain select t1.a from t1 left join t3 on t3.pk1=t1.a and t3.pk2 IS NULL;
drop table t1,t2,t3;

13
sql/opt_table_elimination.cc
View File

@ -490,7 +490,7 @@ void build_eq_mods_for_cond(Func_dep_analyzer *fda, Equality_module **eq_mod,
{
Item *tmp=new Item_null;
if (tmp)
add_eq_mod(fda, eq_mod, *and_level, cond_func, args[0], args[1]);
add_eq_mod(fda, eq_mod, *and_level, cond_func, args[0], tmp);
break;
}
case Item_func::MULT_EQUAL_FUNC:
@ -828,7 +828,7 @@ static Table_value *get_table_value(Func_dep_analyzer *fda, TABLE *table)
{
Table_value *tbl_dep;
if (!(tbl_dep= new Table_value(table)))
return NULL; /* purecov: inspected */
return NULL;
Key_module **key_list= &(tbl_dep->keys);
/* Add dependencies for unique keys */
@ -853,14 +853,7 @@ static Table_value *get_table_value(Func_dep_analyzer *fda, TABLE *table)
static Field_value *get_field_value(Func_dep_analyzer *fda, Field *field)
{
TABLE *table= field->table;
Table_value *tbl_dep;
/* First, get the table*/
if (!(tbl_dep= fda->table_deps[table->tablenr]))
{
if (!(tbl_dep= get_table_value(fda, table)))
return NULL;
}
Table_value *tbl_dep= fda->table_deps[table->tablenr];
/* Try finding the field in field list */
Field_value **pfield= &(tbl_dep->fields);