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MDEV-5884: EXPLAIN UPDATE ... ORDER BY LIMIT shows wrong #rows

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- Make get_index_for_order() return correct #rows. 
  changed EXPLAIN outputs are checked - only #rows is different.
This commit is contained in:
Sergey Petrunya
2014-06-04 00:26:27 +04:00
parent 40da8545a2
commit b6b5b748e7
5 changed files with 36 additions and 12 deletions
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16
mysql-test/r/myisam_explain_non_select_all.result
View File

@ -1172,12 +1172,12 @@ INSERT INTO t1 (i) VALUES (10),(11),(12),(13),(14),(15),(16),(17),(18),(19),
#
EXPLAIN DELETE FROM t1 WHERE i > 10 AND i <= 18 ORDER BY i LIMIT 5;
id select_type table type possible_keys key key_len ref rows Extra
1 SIMPLE t1 range PRIMARY PRIMARY 4 NULL 8 Using where
1 SIMPLE t1 range PRIMARY PRIMARY 4 NULL 5 Using where
FLUSH STATUS;
FLUSH TABLES;
EXPLAIN EXTENDED DELETE FROM t1 WHERE i > 10 AND i <= 18 ORDER BY i LIMIT 5;
id select_type table type possible_keys key key_len ref rows filtered Extra
1 SIMPLE t1 range PRIMARY PRIMARY 4 NULL 8 100.00 Using where
1 SIMPLE t1 range PRIMARY PRIMARY 4 NULL 5 100.00 Using where
# Status of EXPLAIN EXTENDED query
Variable_name Value
FLUSH STATUS;
@ -1479,12 +1479,12 @@ INSERT INTO t2 (i) SELECT i FROM t1;
#
EXPLAIN DELETE FROM t2 WHERE i > 10 AND i <= 18 ORDER BY i DESC LIMIT 5;
id select_type table type possible_keys key key_len ref rows Extra
1 SIMPLE t2 range PRIMARY PRIMARY 4 NULL 8 Using where
1 SIMPLE t2 range PRIMARY PRIMARY 4 NULL 5 Using where
FLUSH STATUS;
FLUSH TABLES;
EXPLAIN EXTENDED DELETE FROM t2 WHERE i > 10 AND i <= 18 ORDER BY i DESC LIMIT 5;
id select_type table type possible_keys key key_len ref rows filtered Extra
1 SIMPLE t2 range PRIMARY PRIMARY 4 NULL 8 100.00 Using where
1 SIMPLE t2 range PRIMARY PRIMARY 4 NULL 5 100.00 Using where
# Status of EXPLAIN EXTENDED query
Variable_name Value
FLUSH STATUS;
@ -1606,12 +1606,12 @@ INSERT INTO t2 (i) SELECT i FROM t1;
#
EXPLAIN UPDATE t2 SET a = 10 WHERE i > 10 AND i <= 18 ORDER BY i LIMIT 5;
id select_type table type possible_keys key key_len ref rows Extra
1 SIMPLE t2 range PRIMARY PRIMARY 4 NULL 8 Using where; Using buffer
1 SIMPLE t2 range PRIMARY PRIMARY 4 NULL 5 Using where; Using buffer
FLUSH STATUS;
FLUSH TABLES;
EXPLAIN EXTENDED UPDATE t2 SET a = 10 WHERE i > 10 AND i <= 18 ORDER BY i LIMIT 5;
id select_type table type possible_keys key key_len ref rows filtered Extra
1 SIMPLE t2 range PRIMARY PRIMARY 4 NULL 8 100.00 Using where; Using buffer
1 SIMPLE t2 range PRIMARY PRIMARY 4 NULL 5 100.00 Using where; Using buffer
# Status of EXPLAIN EXTENDED query
Variable_name Value
FLUSH STATUS;
@ -1915,12 +1915,12 @@ INSERT INTO t2 (i) SELECT i FROM t1;
#
EXPLAIN UPDATE t2 SET a = 10 WHERE i > 10 AND i <= 18 ORDER BY i DESC LIMIT 5;
id select_type table type possible_keys key key_len ref rows Extra
1 SIMPLE t2 range PRIMARY PRIMARY 4 NULL 8 Using where; Using buffer
1 SIMPLE t2 range PRIMARY PRIMARY 4 NULL 5 Using where; Using buffer
FLUSH STATUS;
FLUSH TABLES;
EXPLAIN EXTENDED UPDATE t2 SET a = 10 WHERE i > 10 AND i <= 18 ORDER BY i DESC LIMIT 5;
id select_type table type possible_keys key key_len ref rows filtered Extra
1 SIMPLE t2 range PRIMARY PRIMARY 4 NULL 8 100.00 Using where; Using buffer
1 SIMPLE t2 range PRIMARY PRIMARY 4 NULL 5 100.00 Using where; Using buffer
# Status of EXPLAIN EXTENDED query
Variable_name Value
FLUSH STATUS;

13
mysql-test/r/order_by.result
View File

@ -2936,3 +2936,16 @@ where A.b = B.b
order by A.col2, B.col2 limit 10, 1000000;
drop table t1,t2,t3;
End of 5.5 tests
#
# MDEV-5884: EXPLAIN UPDATE ... ORDER BY LIMIT shows wrong #rows
#
create table t2(a int);
insert into t2 values (0),(1),(2),(3),(4),(5),(6),(7),(8),(9);
create table t1 (key1 int, col1 int, key(key1));
insert into t1
select A.a + 10 * B.a + 100 * C.a, 1234 from t2 A, t2 B, t2 C;
# Should show rows=2, not rows=100
explain update t1 set key1=key1+1 where key1 between 10 and 110 order by key1 limit 2;
id select_type table type possible_keys key key_len ref rows Extra
1 SIMPLE t1 range key1 key1 5 NULL 2 Using where; Using buffer
drop table t1,t2;

2
mysql-test/r/update.result
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@ -615,7 +615,7 @@ select A.a + 10 * B.a + 100 * C.a, 1234 from t2 A, t2 B, t2 C;
explain
update t1 set key1=key1+1 where key1 between 10 and 110 order by key1 limit 2;
id select_type table type possible_keys key key_len ref rows Extra
1 SIMPLE t1 range key1 key1 5 NULL 100 Using where; Using buffer
1 SIMPLE t1 range key1 key1 5 NULL 2 Using where; Using buffer
flush status;
update t1 set key1=key1+1 where key1 between 10 and 110 order by key1 limit 2;
show status like 'Handler_read%';

12
mysql-test/t/order_by.test
View File

@ -1947,4 +1947,14 @@ drop table t1,t2,t3;
--echo End of 5.5 tests
--echo #
--echo # MDEV-5884: EXPLAIN UPDATE ... ORDER BY LIMIT shows wrong #rows
--echo #
create table t2(a int);
insert into t2 values (0),(1),(2),(3),(4),(5),(6),(7),(8),(9);
create table t1 (key1 int, col1 int, key(key1));
insert into t1
select A.a + 10 * B.a + 100 * C.a, 1234 from t2 A, t2 B, t2 C;
--echo # Should show rows=2, not rows=100
explain update t1 set key1=key1+1 where key1 between 10 and 110 order by key1 limit 2;
drop table t1,t2;