November 21, 2014

INSERT INTO … SELECT Performance with Innodb tables.

Everyone using Innodb tables probably got use to the fact Innodb tables perform non locking reads, meaning unless you use some modifiers such as LOCK IN SHARE MODE or FOR UPDATE, SELECT statements will not lock any rows while running. This is generally correct, however there a notable exception – INSERT INTO table1 SELECT * […]

MySQL Replication: ‘Got fatal error 1236′ causes and cures

MySQL replication is a core process for maintaining multiple copies of data – and replication is a very important aspect in database administration. In order to synchronize data between master and slaves you need to make sure that data transfers smoothly, and to do so you need to act promptly regarding replication errors to continue […]

Percona XtraDB Cluster 5.5.34-23.7.6 is now available

Percona is glad to announce the release of Percona XtraDB Cluster 5.5.34-23.7.6 on November 4, 2013. Binaries are available from the downloads area or from our software repositories. Bugs Fixed: Fixed the issues with upgrade on Debian caused by debian-start script. Bug fixed #1112363. Adding the AUTO_INCREMENT column to a table would result in data […]

Recovering temporal types in MySQL 5.6: TIME, TIMESTAMP and DATETIME

MySQL 5.6 introduces a new feature – microseconds resolution in some temporal types. As of 5.6.4 TIME, TIMESTAMP and DATETIME can have a fractional part. To create a field with subseconds you can specify precision in brackets: TIME(3), DATETIME(6) etc. Obviously, the new feature requires the format change. All three types may now have a […]

Recovery after DROP & CREATE

In a very popular data loss scenario a table is dropped and empty one is created with the same name. This is because  mysqldump in many cases generates the “DROP TABLE” instruction before the “CREATE TABLE”:

If there were no subsequent CREATE TABLE the recovery would be trivial. Index_id of the PRIMARY index of […]

Announcing Percona Server 5.5.25a-27.1

Percona is glad to announce the release of Percona Server 5.5.25a-27.1 on July 21st, 2012 (Downloads are available here and from the Percona Software Repositories). Based on MySQL 5.5.25a, including all the bug fixes in it, Percona Server 5.5.25a-27.1 is now the current stable release in the 5.5 series. All of Percona‘s software is open-source and free, all the details of the release can […]

Shard-Query EC2 images available

Infobright and InnoDB AMI images are now available There are now demonstration AMI images for Shard-Query. Each image comes pre-loaded with the data used in the previous Shard-Query blog post. The data in the each image is split into 20 “shards”. This blog post will refer to an EC2 instances as a node from here […]

Ultimate MySQL variable and status reference list

I am constantly referring to the amazing MySQL manual, especially the option and variable reference table. But just as frequently, I want to look up blog posts on variables, or look for content in the Percona documentation or forums. So I present to you what is now my newest Firefox toolbar bookmark: an option and […]

MySQL 5.5.8 and Percona Server: being adaptive

As we can see, MySQL 5.5.8 comes with great improvements and scalability fixes. Adding up all the new features, you have a great release. However, there is one area I want to touch on in this post. At Percona, we consider it important not only to have the best peak performance, but also stable and predictable performance. I refer you […]

Recover BLOB fields

For a long time long types like BLOB, TEXT were not supported by Percona InnoDB Recovery Tool. The reason consists in a special way InnoDB stores BLOBs. An InnoDB table is stored in a clustered index called PRIMARY. It must exist even if a user hasn’t defined the primary index. The PRIMARY index pages are […]