Merge ibabaev@bk-internal.mysql.com:/home/bk/mysql-5.0-opt (75865af6) · Commits · Software / OSDI20 Artifacts / mariadb

mysql-test/r/select.result

+40 −2

Original line number	Diff line number	Diff line
		@@ -2328,9 +2328,9 @@ explain select * from t1 left join t2 on id1 = id2 left join t3 on id1 = id3
		left join t4 on id3 = id4 where id2 = 1 or id4 = 1;
		id select_type table type possible_keys key key_len ref rows Extra
		1 SIMPLE t3 system NULL NULL NULL NULL 0 const row not found
		1 SIMPLE t4 const id4 NULL NULL NULL 1
		1 SIMPLE t1 ALL NULL NULL NULL NULL 2
		1 SIMPLE t2 ALL NULL NULL NULL NULL 1
		1 SIMPLE t4 ALL id4 NULL NULL NULL 1 Using where
		1 SIMPLE t2 ALL NULL NULL NULL NULL 1 Using where
		select * from t1 left join t2 on id1 = id2 left join t3 on id1 = id3
		left join t4 on id3 = id4 where id2 = 1 or id4 = 1;
		id1 id2 id3 id4 id44
		@@ -3479,3 +3479,41 @@ Warning 1466 Leading spaces are removed from name ' a '
		execute stmt;
		a
		1
		CREATE TABLE t1 (a int NOT NULL PRIMARY KEY, b int NOT NULL);
		INSERT INTO t1 VALUES (1,1), (2,2), (3,3), (4,4);
		CREATE TABLE t2 (c int NOT NULL, INDEX idx(c));
		INSERT INTO t2 VALUES
		(1), (1), (1), (1), (1), (1), (1), (1),
		(2), (2), (2), (2),
		(3), (3),
		(4);
		EXPLAIN SELECT b FROM t1, t2 WHERE b=c AND a=1;
		id select_type table type possible_keys key key_len ref rows Extra
		1 SIMPLE t1 const PRIMARY PRIMARY 4 const 1
		1 SIMPLE t2 ref idx idx 4 const 7 Using index
		EXPLAIN SELECT b FROM t1, t2 WHERE b=c AND a=4;
		id select_type table type possible_keys key key_len ref rows Extra
		1 SIMPLE t1 const PRIMARY PRIMARY 4 const 1
		1 SIMPLE t2 ref idx idx 4 const 1 Using index
		DROP TABLE t1, t2;
		CREATE TABLE t1 (id int NOT NULL PRIMARY KEY, a int);
		INSERT INTO t1 VALUES (1,2), (2,NULL), (3,2);
		CREATE TABLE t2 (b int, c INT, INDEX idx1(b));
		INSERT INTO t2 VALUES (2,1), (3,2);
		CREATE TABLE t3 (d int, e int, INDEX idx1(d));
		INSERT INTO t3 VALUES (2,10), (2,20), (1,30), (2,40), (2,50);
		EXPLAIN
		SELECT * FROM t1 LEFT JOIN t2 ON t2.b=t1.a INNER JOIN t3 ON t3.d=t1.id
		WHERE t1.id=2;
		id select_type table type possible_keys key key_len ref rows Extra
		1 SIMPLE t1 const PRIMARY PRIMARY 4 const 1
		1 SIMPLE t2 const idx1 NULL NULL NULL 1
		1 SIMPLE t3 ref idx1 idx1 5 const 3 Using where
		SELECT * FROM t1 LEFT JOIN t2 ON t2.b=t1.a INNER JOIN t3 ON t3.d=t1.id
		WHERE t1.id=2;
		id a b c d e
		2 NULL NULL NULL 2 10
		2 NULL NULL NULL 2 20
		2 NULL NULL NULL 2 40
		2 NULL NULL NULL 2 50
		DROP TABLE t1,t2,t3;

mysql-test/t/select.test

+41 −0

Original line number	Diff line number	Diff line
		@@ -2957,3 +2957,44 @@ SELECT 0.9888889889 * 1.011111411911;
		#
		prepare stmt from 'select 1 as " a "';
		execute stmt;

		#
		# Bug #21390: wrong estimate of rows after elimination of const tables
		#

		CREATE TABLE t1 (a int NOT NULL PRIMARY KEY, b int NOT NULL);
		INSERT INTO t1 VALUES (1,1), (2,2), (3,3), (4,4);

		CREATE TABLE t2 (c int NOT NULL, INDEX idx(c));
		INSERT INTO t2 VALUES
		(1), (1), (1), (1), (1), (1), (1), (1),
		(2), (2), (2), (2),
		(3), (3),
		(4);

		EXPLAIN SELECT b FROM t1, t2 WHERE b=c AND a=1;
		EXPLAIN SELECT b FROM t1, t2 WHERE b=c AND a=4;

		DROP TABLE t1, t2;

		#
		# No matches for a join after substitution of a const table
		#

		CREATE TABLE t1 (id int NOT NULL PRIMARY KEY, a int);
		INSERT INTO t1 VALUES (1,2), (2,NULL), (3,2);

		CREATE TABLE t2 (b int, c INT, INDEX idx1(b));
		INSERT INTO t2 VALUES (2,1), (3,2);

		CREATE TABLE t3 (d int, e int, INDEX idx1(d));
		INSERT INTO t3 VALUES (2,10), (2,20), (1,30), (2,40), (2,50);

		EXPLAIN
		SELECT * FROM t1 LEFT JOIN t2 ON t2.b=t1.a INNER JOIN t3 ON t3.d=t1.id
		WHERE t1.id=2;
		SELECT * FROM t1 LEFT JOIN t2 ON t2.b=t1.a INNER JOIN t3 ON t3.d=t1.id
		WHERE t1.id=2;


		DROP TABLE t1,t2,t3;

sql/sql_select.cc

+54 −24

Original line number	Diff line number	Diff line
		@@ -2205,6 +2205,7 @@ make_join_statistics(JOIN join, TABLE_LIST tables, COND *conds,
		int ref_changed;
		do
		{
		more_const_tables_found:
		ref_changed = 0;
		found_ref=0;

		@@ -2216,6 +2217,30 @@ make_join_statistics(JOIN join, TABLE_LIST tables, COND *conds,
		for (JOIN_TAB *pos=stat_vector+const_count ; (s= pos) ; pos++)
		{
		table=s->table;

		/*
		If equi-join condition by a key is null rejecting and after a
		substitution of a const table the key value happens to be null
		then we can state that there are no matches for this equi-join.
		*/
		if ((keyuse= s->keyuse) && *s->on_expr_ref)
		{
		while (keyuse->table == table)
		{
		if (!(keyuse->val->used_tables() & ~join->const_table_map) &&
		keyuse->val->is_null() && keyuse->null_rejecting)
		{
		s->type= JT_CONST;
		mark_as_null_row(table);
		found_const_table_map\|= table->map;
		join->const_table_map\|= table->map;
		set_position(join,const_count++,s,(KEYUSE*) 0);
		goto more_const_tables_found;
		}
		keyuse++;
		}
		}

		if (s->dependent) // If dependent on some table
		{
		// All dep. must be constants
		@@ -2266,10 +2291,11 @@ make_join_statistics(JOIN join, TABLE_LIST tables, COND *conds,
		} while (keyuse->table == table && keyuse->key == key);

		if (eq_part.is_prefix(table->key_info[key].key_parts) &&
		((table->key_info[key].flags & (HA_NOSAME \| HA_END_SPACE_KEY)) ==
		HA_NOSAME) &&
		!table->fulltext_searched &&
		!table->pos_in_table_list->embedding)
		{
		if ((table->key_info[key].flags & (HA_NOSAME \| HA_END_SPACE_KEY))
		== HA_NOSAME)
		{
		if (const_ref == eq_part)
		{ // Found everything for ref.
		@@ -2294,6 +2320,9 @@ make_join_statistics(JOIN join, TABLE_LIST tables, COND *conds,
		else
		found_ref\|= refs; // Table is const if all refs are const
		}
		else if (const_ref == eq_part)
		s->const_keys.set_bit(key);
		}
		}
		}
		}
		@@ -2696,7 +2725,8 @@ add_key_field(KEY_FIELD *key_fields,uint and_level, Item_func cond,
		We use null_rejecting in add_not_null_conds() to add
		'othertbl.field IS NOT NULL' to tab->select_cond.
		*/
		(*key_fields)->null_rejecting= ((cond->functype() == Item_func::EQ_FUNC) &&
		(*key_fields)->null_rejecting= ((cond->functype() == Item_func::EQ_FUNC \|\|
		cond->functype() == Item_func::MULT_EQUAL_FUNC) &&
		((*value)->type() == Item::FIELD_ITEM) &&
		((Item_field)value)->field->maybe_null());
		(*key_fields)++;
		@@ -3461,7 +3491,7 @@ best_access_path(JOIN *join,
		keyuse->used_tables));
		if (tmp < best_prev_record_reads)
		{
		best_part_found_ref= keyuse->used_tables;
		best_part_found_ref= keyuse->used_tables & ~join->const_table_map;
		best_prev_record_reads= tmp;
		}
		if (rec > keyuse->ref_table_rows)