Skip to content

Commit

Permalink
MDEV-20531: innodb.temporary_table_optimisation fails
Browse files Browse the repository at this point in the history
Try to use more deterministic floating-point operations.
Apparently, 2.2 > 2.2 wrongly holds on many platforms, but
not ppc64le on the compiler used on Red Had Enterprise Linux 8.
The reason could be an infinite binary presentation:
2.2 = 0b10.001100110011…

With t1_f = 2.5 = 0b10.1, t1_f > 2.5 would no longer hold on AMD64.
Let us replace the 2.2 with 2.5 and compare t1_f >= 2.5 in order to
get more consistent results across all platforms.
  • Loading branch information
dr-m committed Sep 9, 2019
1 parent f9f9685 commit 7591a24
Show file tree
Hide file tree
Showing 2 changed files with 13 additions and 13 deletions.
18 changes: 9 additions & 9 deletions mysql-test/suite/innodb/r/temporary_table_optimization.result
Original file line number Diff line number Diff line change
Expand Up @@ -112,7 +112,7 @@ count(*)
drop table t1;
drop procedure populate_t1;
create temporary table t1 (t1_i int, t1_f float) engine = innodb;
insert into t1 values (1, 1.1), (2, 2.2), (3, 2.2), (4, 4.4);
insert into t1 values (1, 1.1), (2, 2.5), (3, 2.5), (4, 4.4);
explain select * from t1 where t1_i = 1;
id select_type table type possible_keys key key_len ref rows Extra
1 SIMPLE t1 ALL NULL NULL NULL NULL 4 Using where
Expand All @@ -124,22 +124,22 @@ select * from t1 where t1_i = 1;
t1_i t1_f
1 1.1
alter table t1 add unique index sec_index(t1_f);
ERROR 23000: Duplicate entry '2.2' for key 'sec_index'
ERROR 23000: Duplicate entry '2.5' for key 'sec_index'
alter table t1 add index sec_index(t1_f);
explain select * from t1 where t1_f > 2.2;
explain select * from t1 where t1_f >= 2.5;
id select_type table type possible_keys key key_len ref rows Extra
1 SIMPLE t1 ALL sec_index NULL NULL NULL 4 Using where
select * from t1 where t1_f > 2.2;
select * from t1 where t1_f >= 2.5;
t1_i t1_f
2 2.2
3 2.2
2 2.5
3 2.5
4 4.4
alter table t1 add column (t1_c char(10));
select * from t1;
t1_i t1_f t1_c
1 1.1 NULL
2 2.2 NULL
3 2.2 NULL
2 2.5 NULL
3 2.5 NULL
4 4.4 NULL
insert into t1 values (5, 5.5, 'krunal');
alter table t1 drop column t1_f;
Expand All @@ -150,7 +150,7 @@ t1 CREATE TEMPORARY TABLE `t1` (
`t1_c` char(10) DEFAULT NULL,
UNIQUE KEY `pri_index` (`t1_i`)
) ENGINE=InnoDB DEFAULT CHARSET=latin1
select * from t1 where t1_f > 2.2;
select * from t1 where t1_f >= 2.5;
ERROR 42S22: Unknown column 't1_f' in 'where clause'
alter table t1 add index sec_index2(t1_c), algorithm=inplace;
ERROR 0A000: ALGORITHM=INPLACE is not supported for this operation. Try ALGORITHM=COPY
Expand Down
8 changes: 4 additions & 4 deletions mysql-test/suite/innodb/t/temporary_table_optimization.test
Original file line number Diff line number Diff line change
Expand Up @@ -100,7 +100,7 @@ drop procedure populate_t1;
# 3. Alter of temp-table.
#
create temporary table t1 (t1_i int, t1_f float) engine = innodb;
insert into t1 values (1, 1.1), (2, 2.2), (3, 2.2), (4, 4.4);
insert into t1 values (1, 1.1), (2, 2.5), (3, 2.5), (4, 4.4);
#
explain select * from t1 where t1_i = 1;
alter table t1 add unique index pri_index(t1_i);
Expand All @@ -110,8 +110,8 @@ select * from t1 where t1_i = 1;
--error ER_DUP_ENTRY
alter table t1 add unique index sec_index(t1_f);
alter table t1 add index sec_index(t1_f);
explain select * from t1 where t1_f > 2.2;
select * from t1 where t1_f > 2.2;
explain select * from t1 where t1_f >= 2.5;
select * from t1 where t1_f >= 2.5;
#
alter table t1 add column (t1_c char(10));
select * from t1;
Expand All @@ -120,7 +120,7 @@ insert into t1 values (5, 5.5, 'krunal');
alter table t1 drop column t1_f;
show create table t1;
--error ER_BAD_FIELD_ERROR
select * from t1 where t1_f > 2.2;
select * from t1 where t1_f >= 2.5;
#
--error ER_ALTER_OPERATION_NOT_SUPPORTED
alter table t1 add index sec_index2(t1_c), algorithm=inplace;
Expand Down

0 comments on commit 7591a24

Please sign in to comment.