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fixed bug in used_tables() report of left expression of IN subquery

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fixed number of rows of external field reported to optimizer
added check of choosen key (checked left expression tag)
(SCRUM fix for simple IN optimisation)


mysql-test/r/subselect.result:
  new EXPLAIN results ufter fixing used_tables() of Item_cache
sql/item_cmpfunc.cc:
  fixed used_tables asignment
sql/item_subselect.cc:
  added left expression referenca tag
sql/item_subselect.h:
  fixed layout
sql/mysql_priv.h:
  left expression reference tag
sql/mysqld.cc:
  left expression reference tag
sql/sql_select.cc:
  checked left expression reference tag
  fixed number of rows in outer reference (it should be constant)
This commit is contained in:
unknown
2003-08-07 11:16:02 +03:00
parent 4a8ab8ac56
commit 57e31f158b
7 changed files with 43 additions and 29 deletions
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16
sql/sql_select.cc
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@ -772,7 +772,8 @@ JOIN::optimize()
if (!having)
{
Item *where= 0;
if (join_tab[0].type == JT_EQ_REF)
if (join_tab[0].type == JT_EQ_REF &&
join_tab[0].ref.items[0]->name == in_left_expr_name)
{
if (test_in_subselect(&where))
{
@ -785,7 +786,8 @@ JOIN::optimize()
where)));
}
}
else if (join_tab[0].type == JT_REF)
else if (join_tab[0].type == JT_REF &&
join_tab[0].ref.items[0]->name == in_left_expr_name)
{
if (test_in_subselect(&where))
{
@ -800,6 +802,7 @@ JOIN::optimize()
}
}
} else if (join_tab[0].type == JT_REF_OR_NULL &&
join_tab[0].ref.items[0]->name == in_left_expr_name &&
having->type() == Item::FUNC_ITEM &&
((Item_func *) having)->functype() ==
Item_func::ISNOTNULLTEST_FUNC)
@ -2347,7 +2350,8 @@ sort_keyuse(KEYUSE *a,KEYUSE *b)
if (a->keypart != b->keypart)
return (int) (a->keypart - b->keypart);
// Place const values before other ones
if ((res= test(a->used_tables) - test(b->used_tables)))
if ((res= test((a->used_tables & ~OUTER_REF_TABLE_BIT)) -
test((b->used_tables & ~OUTER_REF_TABLE_BIT))))
return res;
/* Place rows that are not 'OPTIMIZE_REF_OR_NULL' first */
return (int) ((a->optimize & KEY_OPTIMIZE_REF_OR_NULL) -
@ -2478,6 +2482,12 @@ static void optimize_keyuse(JOIN *join, DYNAMIC_ARRAY *keyuse_array)
keyuse->ref_table_rows= max(tmp_table->file->records, 100);
}
}
/*
Outer reference (external field) is constant for single executing
of subquery
*/
if (keyuse->used_tables == OUTER_REF_TABLE_BIT)
keyuse->ref_table_rows= 1;
}
}