Details
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Bug
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Status: Closed (View Workflow)
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Major
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Resolution: Fixed
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10.0, 10.1
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10.0.14-MariaDB installed via homebrew on OS X 10.10.3
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10.0.23
Description
According to https://dev.mysql.com/doc/refman/5.6/en/innodb-sys-tablestats-table.html (can't find the corresponding MariaDB documentation), the MODIFIED_COUNTER value in information_schema.INNODB_SYS_TABLESTATS is supposed to change on all DML operations. However, the value doesn't change when I issue an UPDATE on an InnoDB table:
MariaDB [baz]> SELECT `name`, `num_rows`, `modified_counter` FROM `information_schema`.`innodb_sys_tablestats` WHERE `name` = 'baz/foo';
|
+---------+----------+------------------+
|
| name | num_rows | modified_counter |
|
+---------+----------+------------------+
|
| baz/foo | 8 | 3 |
|
+---------+----------+------------------+
|
1 row in set (0.00 sec)
|
|
|
MariaDB [baz]> insert into foo (id, bar) values (1, '');
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Query OK, 1 row affected (0.00 sec)
|
|
|
MariaDB [baz]> SELECT `name`, `num_rows`, `modified_counter` FROM `information_schema`.`innodb_sys_tablestats` WHERE `name` = 'baz/foo';
|
+---------+----------+------------------+
|
| name | num_rows | modified_counter |
|
+---------+----------+------------------+
|
| baz/foo | 9 | 4 |
|
+---------+----------+------------------+
|
1 row in set (0.00 sec)
|
|
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MariaDB [baz]> update foo set bar='A' where id=1;
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Query OK, 1 row affected (0.01 sec)
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Rows matched: 1 Changed: 1 Warnings: 0
|
|
|
MariaDB [baz]> SELECT `name`, `num_rows`, `modified_counter` FROM `information_schema`.`innodb_sys_tablestats` WHERE `name` = 'baz/foo';
|
+---------+----------+------------------+
|
| name | num_rows | modified_counter |
|
+---------+----------+------------------+
|
| baz/foo | 9 | 4 |
|
+---------+----------+------------------+
|
1 row in set (0.00 sec)
|
|
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MariaDB [baz]> update foo set bar='B' where id=1;
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Query OK, 1 row affected (0.01 sec)
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Rows matched: 1 Changed: 1 Warnings: 0
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|
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MariaDB [baz]> SELECT `name`, `num_rows`, `modified_counter` FROM `information_schema`.`innodb_sys_tablestats` WHERE `name` = 'baz/foo';
|
+---------+----------+------------------+
|
| name | num_rows | modified_counter |
|
+---------+----------+------------------+
|
| baz/foo | 9 | 4 |
|
+---------+----------+------------------+
|
1 row in set (0.00 sec)
|
|
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MariaDB [baz]> delete from foo where id=1;
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Query OK, 1 row affected (0.01 sec)
|
|
|
MariaDB [baz]> SELECT `name`, `num_rows`, `modified_counter` FROM `information_schema`.`innodb_sys_tablestats` WHERE `name` = 'baz/foo';
|
+---------+----------+------------------+
|
| name | num_rows | modified_counter |
|
+---------+----------+------------------+
|
| baz/foo | 8 | 5 |
|
+---------+----------+------------------+
|
1 row in set (0.00 sec)
|
I was expecting modified_counter to also change on the UPDATE statements.
I'm trying to use these two values to emulate CHECKSUM TABLE foo QUICK; from MyISAM, to monitor for data changes to an InnoDB table.