Details
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Bug
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Status: Closed (View Workflow)
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Critical
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Resolution: Fixed
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10.0.2, 5.5.31, 5.1.67, 5.2.14, 5.3.12, 10.2(EOL), 10.3(EOL), 10.4(EOL), 10.5, 10.6, 10.7(EOL)
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Gentoo linux - Mariadb-5.5.31-log
Windows 7 - MariaDB-5.5.28
Description
Hi,
I'm trying to get index info from information_schema.statistics
but, if I try to get collation field, it always returns null.
Test case
create table test.some_table (field1 int unsigned not null, field2 varchar(64), primary key (field1), key(field2)); |
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/* collation with their correct value */
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select * from information_schema.STATISTICS where table_name='some_table' and table_schema='test'; |
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/* collation is null here */
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select table_schema, table_name, index_name, column_name, collation |
from information_schema.STATISTICS |
where table_schema='test' and table_name='some_table'; |
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/* collation (quoted) is null here */
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select table_schema, table_name, index_name, column_name, `collation` |
from information_schema.STATISTICS |
where table_schema='test' and table_name='some_table'; |
Attachments
Issue Links
- relates to
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MDEV-13756 Implement descending index: KEY (a DESC, b ASC)
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- Closed
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- links to
Activity
Now when with the development of MDEV-13756 INFORMATION_SCHEMA.STATISTICS.COLLATION starts meaning something, I think it needs to be fixed.
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preview-10.8-MDEV-13756-desc-indexes c13c1079b |
MariaDB [test]> create or replace table t (a int, b int, key(a), key(b desc)); |
Query OK, 0 rows affected (0.107 sec) |
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MariaDB [test]> select index_name, column_name, collation from information_schema.statistics where table_name = 't'; |
+------------+-------------+-----------+ |
| index_name | column_name | collation |
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+------------+-------------+-----------+ |
| a | a | NULL | |
| b | b | NULL | |
+------------+-------------+-----------+ |
2 rows in set (0.002 sec) |
The upstream bug was fixed in 8.0.
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MySQL 8.0 |
MySQL [test]> create table t (a int, b int, key(a), key(b desc)); |
Query OK, 0 rows affected (0.244 sec) |
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MySQL [test]> select index_name, column_name, collation from information_schema.statistics where table_name = 't'; |
+------------+-------------+-----------+ |
| INDEX_NAME | COLUMN_NAME | COLLATION |
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+------------+-------------+-----------+ |
| a | a | A |
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| b | b | D |
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+------------+-------------+-----------+ |
2 rows in set (0.007 sec) |
Also reproducible on all of MySQL 5.1 - 5.7 (MySQL bug #65121)