Matt Lord already announced this change, but I am so happy, so want to repeat. MySQL Community Bugs Database Team introduced new button "Affects Me". After you click this button, counter, assigned to each of bug reports, will increase by one. This means we: MySQL Support and Engineering, - will see how many users are affected by the bug.

Why is this important? We have always considered community input as we prioritize bug fixes, and this is one more point of reference for us. Before this change we only had a counter for support customers which increased when they opened a support request, complaining they are affected by a bug. But our customers are smart and not always open support request when hit a bug: sometimes they simply implement workaround. Or there could be other circumstances when they don't …

My MySQL bugs is a list I recently created and intend to keep up to date with issues I have seen.

Shard-Query examines INFORMATION_SCHEMA.PARTITIONS to determine if a table is partitioned.  When a table is partitioned, Shard-Query creates multiple background queries, each limited to a single partition.  Unfortunately, it seems that examining INFORMATION_SCHEMA.PARTITIONS causes query plans to change after the view is accessed.

I have reported bug 69179 to MySQL AB  Oracle Corporation(old habits die hard).

Be careful: If you have automated tools (like schema management GUI tools) then make sure they don’t examine INFORMATION_SCHEMA.PARTITIONS or you may get bad plans until you analyze your tables or restart the database, even if using persistent stats.

I can only get the bug to happen when a WHERE clause is issued that limits access to a single partition.  It may be that the per partition statistics …

Some bugs can have a high impact if it causes data corruption, security issues or simply causes MySQL to crash. But what about small bugs and small usability issues?

This entry from the MySQL 5.6.8 release notes is an interesting one:
InnoDB: On startup, MySQL would not start if there was a mismatch between the value of the innodb_log_file_size configuration option and the actual size of the ib_logfile* files that make up the redo log. This behavior required manually removing the redo log files after changing the value of innodb_log_file_size. The fix causes MySQL to write all …

MySQL lets database administrators define access rights on many levels – from the ability to run global commands down to access to individual columns. Some rights can be applied to many different objects, such as for example SELECT or UPDATE, which can be granted globally or restricted only to certain databases or tables, while others are only meant for one specific purpose. An example of the latter could be FILE privilege, which permits user to interact with the file system from inside a database instance. It only makes sense as the global right and not anywhere else.

As any other activity that produces changes, GRANT statements are replicated to MySQL slaves. Regardless of the binary log format setting, such events are always logged in STATEMENT format. It is likely because the command needs to handle more than just updating the contents of a few system tables, so such design allows each slave to fully execute the changes within their …

I discovered a feature (or bug) of MySQL timestamp fields. Maybe is documented in some place what I not read yet:

When I add a new timestamp field to a table, MySQL magically adds some features to new timestamp field like a “trigger” and a default value to CURRENT_TIMESTAMP.

There is test-case script:

-- CREATING TABLE AND INSERT SOME DUMMY DATA
mysql> CREATE TABLE t(
    -> id INT NOT NULL PRIMARY KEY AUTO_INCREMENT,
    -> val VARCHAR(50)
    -> );
Query OK, 0 ROWS affected (0.15 sec)
 
mysql> INSERT INTO t (val) VALUES ("foo") ,("var");
Query OK, 2 ROWS affected (0.08 sec)
Records: 2  Duplicates: 0  Warnings: 0
 
mysql> SELECT * FROM t;
+----+------+
| id | val  |
+----+------+
|  1 | foo  |
|  2 | var  |
+----+------+
2 ROWS IN SET (0.00 sec)
 
 
-- ADDING NEW TIMESTAMP FIELD AND ADD MORE DUMMY DATA
mysql> ALTER TABLE t ADD ts_field TIMESTAMP;
Query OK, 2 ROWS affected (0.35 sec)
Records: 2  Duplicates: 0 …

I pledged, in my first post last month, that SkySQL will do its part to promote the best of MySQL and its community. Given the recent discovery that Oracle is no longer publishing test cases for bug fixes, and the dialogue surrounding it, it feels like the right time to share my thoughts on what this means to the open source collective, and what we can do – and are doing – about it.

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There has been a lot of talk about MySQL 5.6 replication improvements. With few exceptions, what I have seen was either marketing messages or hearsay. This means that few people have really tried out the new features to see whether they meet the users needs.

As usual, I did try the new version in my environment. I like to form my own opinion based on experiments, and so I have been trying out these features since they have appeared in early milestones.

What follows is a list of (potentially) surprising results that you may get when using MySQL 5.6.
All the examples are made using MySQL 5.6.6.

Gotcha #1 : too much noise

I have already mentioned that MySQL 5.6 is too verbose when creating data directory. This also means that your error log may have way more information than you'd like to get. …

This is the third time MySQL has made an entry into the Oracle Critical Patch Update Advisory service. The first time, we at Team MariaDB came up with an analysis: Oracle’s 27 MySQL security fixes and MariaDB.

Security is important to a DBA. Having vague explanations does no one any good. Even Oracle ACE Director Ronald Bradford chooses to ask some tough questions on this issue. Recently we found a bug in MySQL & MariaDB and did some …

There are mistakes that drive you crazy when you try to understand what went wrong.

One of the most annoying and hard to catch was this, apparently harmless line:

tungsten-sandbox -m 5.5.24 --topology all-masters -n 2 -p 7300 -l 12300 -r 10300 –t $HOME/mm -d tsb-mm

The person reporting the error told me that the installation directory (indicated by "-t") was not taken into account.

I usually debug by examples, so I copied the line, and pasted it into one of my servers. Sure enough, the application did not take trat option into account. The installation kept happening in the default directory.

I knew that I had done a good job at making the application configurable, but I checked the code nonetheless. The only place where the default directory is mentioned is when the related variable is initialized. Throughout the code, there are no literal values used for this purpose. And yet, the …