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MDEV-28858 Wrong result with table elimination combined with not_null_range_scan

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The bug was that build_notnull_conds_for_range_scans() did not take into
account the join_tab is not yet sorted with constant tables first.
Fixed the bug by testing explicitely if a table is a const table.
This commit is contained in:
Monty
2022-06-15 23:49:09 +03:00
parent 27309fc6b0
commit 674842bee0
4 changed files with 64 additions and 6 deletions
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19
mysql-test/main/range.result
View File

@ -3635,6 +3635,25 @@ SELECT * FROM t1 LEFT JOIN t2 ON a = pk WHERE b >= 0 AND pk IS NULL;
a pk b
DROP TABLE t1, t2;
SET @@optimizer_switch= @save_optimizer_switch;
# MDEV-28858 Wrong result with table elimination combined with
# not_null_range_scan
#
CREATE TABLE t1 (a INT, b INT) ENGINE=MyISAM;
INSERT INTO t1 VALUES (10,1),(null,2);
CREATE TABLE t2 (pk INT PRIMARY KEY) ENGINE=MyISAM;
INSERT INTO t2 VALUES (1),(2);
SET @save_optimizer_switch= @@optimizer_switch;
SET optimizer_switch= 'not_null_range_scan=on';
SELECT t1.b FROM t1 LEFT JOIN t2 ON t1.a = t2.pk WHERE t1.a IS NULL ORDER BY t1.b;
b
2
SET optimizer_switch= 'not_null_range_scan=off';
SELECT t1.b FROM t1 LEFT JOIN t2 ON t1.a = t2.pk WHERE t1.a IS NULL ORDER BY t1.b;
b
2
SET @@optimizer_switch=@save_optimizer_switch;
drop table t1,t2;
#
# End of 10.5 tests
#

18
mysql-test/main/range.test
View File

@ -2492,6 +2492,24 @@ DROP TABLE t1, t2;
SET @@optimizer_switch= @save_optimizer_switch;
--echo
--echo # MDEV-28858 Wrong result with table elimination combined with
--echo # not_null_range_scan
--echo #
CREATE TABLE t1 (a INT, b INT) ENGINE=MyISAM;
INSERT INTO t1 VALUES (10,1),(null,2);
CREATE TABLE t2 (pk INT PRIMARY KEY) ENGINE=MyISAM;
INSERT INTO t2 VALUES (1),(2);
SET @save_optimizer_switch= @@optimizer_switch;
SET optimizer_switch= 'not_null_range_scan=on';
SELECT t1.b FROM t1 LEFT JOIN t2 ON t1.a = t2.pk WHERE t1.a IS NULL ORDER BY t1.b;
SET optimizer_switch= 'not_null_range_scan=off';
SELECT t1.b FROM t1 LEFT JOIN t2 ON t1.a = t2.pk WHERE t1.a IS NULL ORDER BY t1.b;
SET @@optimizer_switch=@save_optimizer_switch;
drop table t1,t2;
--echo #
--echo # End of 10.5 tests
--echo #

19
mysql-test/main/range_mrr_icp.result
View File

@ -3624,6 +3624,25 @@ SELECT * FROM t1 LEFT JOIN t2 ON a = pk WHERE b >= 0 AND pk IS NULL;
a pk b
DROP TABLE t1, t2;
SET @@optimizer_switch= @save_optimizer_switch;
# MDEV-28858 Wrong result with table elimination combined with
# not_null_range_scan
#
CREATE TABLE t1 (a INT, b INT) ENGINE=MyISAM;
INSERT INTO t1 VALUES (10,1),(null,2);
CREATE TABLE t2 (pk INT PRIMARY KEY) ENGINE=MyISAM;
INSERT INTO t2 VALUES (1),(2);
SET @save_optimizer_switch= @@optimizer_switch;
SET optimizer_switch= 'not_null_range_scan=on';
SELECT t1.b FROM t1 LEFT JOIN t2 ON t1.a = t2.pk WHERE t1.a IS NULL ORDER BY t1.b;
b
2
SET optimizer_switch= 'not_null_range_scan=off';
SELECT t1.b FROM t1 LEFT JOIN t2 ON t1.a = t2.pk WHERE t1.a IS NULL ORDER BY t1.b;
b
2
SET @@optimizer_switch=@save_optimizer_switch;
drop table t1,t2;
#
# End of 10.5 tests
#

14
sql/sql_select.cc
View File

@ -29573,11 +29573,12 @@ bool build_notnull_conds_for_range_scans(JOIN *join, Item *cond,
DBUG_ENTER("build_notnull_conds_for_range_scans");
for (JOIN_TAB *s= join->join_tab + join->const_tables ;
for (JOIN_TAB *s= join->join_tab;
s < join->join_tab + join->table_count ; s++)
{
/* Clear all needed bitmaps to mark found fields */
if (allowed & s->table->map)
if ((allowed & s->table->map) &&
!(s->table->map && join->const_table_map))
bitmap_clear_all(&s->table->tmp_set);
}
@ -29592,17 +29593,18 @@ bool build_notnull_conds_for_range_scans(JOIN *join, Item *cond,
For each table t from 'allowed' build a conjunction of NOT NULL predicates
constructed for all found fields if they are included in some indexes.
If the construction of the conjunction succeeds attach the formula to
t->table->notnull_cond. The condition will be used to look for complementary
range scans.
t->table->notnull_cond. The condition will be used to look for
complementary range scans.
*/
for (JOIN_TAB *s= join->join_tab + join->const_tables ;
for (JOIN_TAB *s= join->join_tab ;
s < join->join_tab + join->table_count ; s++)
{
TABLE *tab= s->table;
List<Item> notnull_list;
Item *notnull_cond= 0;
if (!(allowed & tab->map))
if (!(allowed & tab->map) ||
(s->table->map && join->const_table_map))
continue;
for (Field** field_ptr= tab->field; *field_ptr; field_ptr++)