MySQL

mysql.com and related sites are down

I tried to go to mysql.com and Planet MySQL over my lunch break at OSCON 2009 to find the websites are down. Seems from conversions with fellow Drizzle colleagues this has been down for some time.

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Drizzle Query logging

Currently Drizzle offers three (3) separate query logging plugins. These plugins offer an extensible means of gathering all or selected queries and provide the foundation for a query analyser tool. Additional filtering includes selecting queries by execution time, result size, rows processed and by any given regular expression via PCRE.

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What’s new in MySQL 5.4.1

Absolutely nothing? 5.4.0 was released with a change in the MySQL Binary distributions , delivering only 1 64bit Linux platform and two Sun Solaris platforms. This was officially announced on April 21 2009 however the 5.

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What to do at 3:25am

Look at MySQL bug reports of course? Well actually I’m writing multiple blog posts, and I was confirming additional reference sources and links when I came across MySQL Bug #29847 – Large CPU usage of InnoDB crash recovery with a big buf pool.

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Never let your binlog directory fill up

Recently with a client while running a number of disaster recovery tests I came across a nasty situation which was not part of the original plan and provided a far worse disaster situation then expected.

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Understanding more InnoDB MVCC

As I had written earlier in Understanding InnoDB MVCC , I am trying to understand why InnoDB is taking a lock on data during an UPDATE when I do not expect this to happen.

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Understanding InnoDB MVCC

Multi versioning concurrency control (MVCC) is a database design theory that enables relational databases to support concurrency, or more simply multiple user access to common data in your database. In MySQL the InnoDB storage engine provides MVCC, row-level locking, full ACID compliance as well as other features.

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Killing my softly with QUERY

The MySQL KILL command as the name suggests kills queries that are running. After identifying the Id using the SHOW PROCESSLIST command, the User of the connection/thread or a database user with SUPER privileges can execute KILL [id]; to remove the connection/thread.

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An important Drizzle/MySQL difference

There are many features that are similar in MySQL and Drizzle. There are also many that are not. I’ve previously discussed topics like Datatypes and tables , SQL_MODE and SHOW .

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The confusion over global and session status

I was trying to demonstrate to a client how to monitor queries that generate internal temporary tables. With an EXPLAIN plan you see ‘Creating temporary’. Within MySQL you can use the SHOW STATUS to look at queries that create temporary tables.

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Benchmarking Drizzle with MyBench(DBD::drizzle)

With thanks to Patrick Galbraith and his DBD::drizzle 0.200 I am now able to test client benchmarks side by side with MySQL and Drizzle. For simple benchmarking with clients, generally when I have little time, I use a simple Perl framework mybench .

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Verifying MySQL Replication in action

There is a very simple test to show MySQL replication in action and to also better understand the basics of MySQL Replication. With a configured MySQL environment we can run the following test on your MySQL master, and monitor the MySQL slave.

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Using statpack with SHOW STATUS

Mark Leith, on of the MySQL Support Team managers wrote some time ago a very nice utility I use often called Statpack . My use of Statpack is very simple. Take two snaphots of SHOW GLOBAL STATUS and compare to produce a text based version of the statistics.

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The value of multi insert values

Baron got a great amount of response from his 50 things to know before migrating Oracle to MySQL . I’m glad I invited him as a fellow MySQL colleague to my presentation to the Federal Government on Best Practices for Migrating to MySQL from Oracle and SQL Server for his inspiration.

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