On Friday I gave a presentation on “MySQL Query Patterns, Optimized” for Percona MySQL Webinars. If you missed it, you can still…, and reinitializing the sequence after making certain insert/update/delete operations. If you have a dataset that changes infrequently, then this… each kind_id. It was more efficient in this case to force MySQL to scan the `title` table first, grouping by kind_id…
Post: trx descriptors: MySQL performance improvements in Percona Server 5.5.30-30.2
April 12, 2013 By 3 Comments
… of the list scan by replacing it with more efficient operations. In a nutshell, it maintains an array of active transactions…, applies only to the following kinds of transactions: MySQL transactions started with START TRANSACTION READ ONLY MySQL transactions created by a non-locking… perfect case for read-only optimization in MySQL 5.6 and as you can see MySQL 5.6 shines in this benchmark…
Post: Virident vCache vs. FlashCache: Part 1
May 16, 2013 By 3 Comments
… to conduct some benchmarks for the use case where the MySQL working set is significantly larger than the InnoDB buffer pool… to syslog as the operation proceeds, the device never reports that it’s actually finished. I think both kinds of flushing are… something that could prove useful in certain situations. Winner: FlashCache. Operational Monitoring: Both solutions offer plenty of statistics; the main difference…
Post: Implications of Metadata Locking Changes in MySQL 5.5
February 1, 2013 By 9 Comments
… Locking behavior prior to MySQL 5.5.3 Metadata Locking behavior prior to MySQL 5.5.3 Prior to MySQL 5.5.3… you can see that the table is blocked for any kind of operation. Let’s see the profiling information for one of… query to a table that has a DDL operation waiting, will block. Why? Because MySQL sees that the old entries in the…
Post: Helgrinding MySQL with InnoDB for Synchronisation Errors, Fun and Profit
November 24, 2011 By 2 Comments
…. Now, Valgrind does not need much introduction, especially to the MySQL server developers. The Valgrind Memcheck tool, which is synonymous with…-55.patch Now let’s see what kind of goodies does Helgrind find on MySQL server. Let’s take a recent 5…-minor. Additionally, I’d consider backporting and using MySQL 5.5 atomic operation primitives with proper memory barriers, so that there is…
Post: MySQL Life Cycle. Your Feedback is needed.
November 18, 2011 By 6 Comments
… what kind of Version and Platform support do you think is adequate for MySQL ? Oracle seems to have extended support for MySQL versions… as people doing major MySQL upgrade usually would have an option to upgrade operating system as well Or is MySQL Upgrade to new version while sticking to very old operating system is important…
Post: Two Types of MySQL Users
May 10, 2010 By 5 Comments
… cool you want your database operation to be ? Visiting customers I see 2 very distinct groups of MySQL Users Users what want… not done before, they are interested in all kinds of plugins, replicating from MySQL to Cassandra and doing other cool stuff. Some… quick learning curve is robust and easy to operate and has few surprises. As MySQL matures and gets more and more used…
Post: Troubleshooting MySQL Memory Usage
March 21, 2012 By 5 Comments
… total any more as Innodb has moved allocating memory from operation system directly not from addition memory pool (hence 0). Such… Leaks There are many kinds of memory leaks and I would say these are rather rare in MySQL. Most suspected memory leaks… and fixed. This is where your MySQL Support contract can be handy. Conclusion Understanding where MySQL can allocate memory can help us…
Post: Is there room for more MySQL IO Optimization?
January 3, 2013 By 11 Comments
…files, binary log, FRM files, MySQL MyISAM system tables etc. Starting MySQL 5.5 MySQL uses asynchronous IO which … workloads such cases are rare – most OLTP kind of workloads indeed work better with O_DIRECT… here as O_DIRECT only applies to operating system logic while RAID controller may be …
Post: Troubleshooting MySQL Upgrade Performance Regressions
February 15, 2012 By Leave a Comment
… not do. You should not panic and go change all kind of configuration options in case you get lucky. Sometimes you… MySQL upgrade – version change but in a lot of cases this will happen when settings are changed at the same time, operating… it without side load. Setting up 2 MySQL Servers side by side (for example with MySQL Sandbox) can especially be helpful. Once…
