A common practice to offload traffic from MySQL 5.6 is to use a caching layer to store expensive result sets or objects. Some typical use cases include: Complicated query result set (search results, recent users, recent posts, etc) Full page output (relatively static pages) Full objects (user or cart object built from several queries) Infrequently [...]
MySQL 5.6.10 Optimizer Limitations: Index Condition Pushdown
March 14, 2013 By 2 Comments
While preparing the webinar I will deliver this Friday, I ran into a quite interesting (although not very impacting) optimizer issue: a “SELECT *” taking half the time to execute than the same “SELECT one_indexed_column” query in MySQL 5.6.10. This turned into a really nice exercise for checking the performance and inner workings of one [...]
MySQL 5.6 vs MySQL 5.5 and the Star Schema Benchmark
March 11, 2013 By 7 Comments
So far most of the benchmarks posted about MySQL 5.6 use the sysbench OLTP workload. I wanted to test a set of queries which, unlike sysbench, utilize joins. I also wanted an easily reproducible set of data which is more rich than the simple sysbench table. The Star Schema Benchmark (SSB) seems ideal for this. [...]
Analyzing Slow Query Table in MySQL 5.6
February 18, 2013 By 1 Comment
Next week I’m teaching an online Percona Training class, called Analyzing SQL Queries with Percona Toolkit. This is a guided tour of best practices for pt-query-digest, the best tool for evaluating where your database response time is being spent. This month we saw the GA release of MySQL 5.6, and I wanted to check if any [...]
Implications of Metadata Locking Changes in MySQL 5.5
February 1, 2013 By 9 Comments
While most of the talk recently has mostly been around the new changes in MySQL 5.6 (and that is understandable), I have had lately some very interesting cases to deal with, with respect to the Metadata Locking related changes that were introduced in MySQL 5.5.3. It appears that the implications of Metadata Locking have not [...]
Percona XtraDB Cluster: Multi-node writing and Unexpected deadlocks
August 17, 2012 By 17 Comments
Percona XtraDB Cluster (PXC) and the technology it uses (Galera) is an exciting alternative to traditional MySQL replication. For those who don’t know, it gives you: Fully Synchronous replication with a write latency increase equivalent to a ping RTT to the furthest node Automatic cluster synchronization, both incremental and full restores The ability to read [...]
MySQL Indexing Best Practices: Webinar Questions Followup
August 16, 2012 By 4 Comments
I had a lot of questions on my MySQL Indexing: Best Practices Webinar (both recording and slides are available now) We had lots of questions. I did not have time to answer some and others are better answered in writing anyway. Q: One developer on our team wants to replace longish (25-30) indexed varchars with [...]
Announcing Percona Server 5.5.25a-27.1
July 21, 2012 By Leave a Comment
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 [...]
Join Optimizations in MySQL 5.6 and MariaDB 5.5
April 4, 2012 By 4 Comments
This is the third blog post in the series of blog posts leading up to the talk comparing the optimizer enhancements in MySQL 5.6 and MariaDB 5.5. This blog post is targeted at the join related optimizations introduced in the optimizer. These optimizations are available in both MySQL 5.6 and MariaDB 5.5, and MariaDB 5.5 [...]
Troubleshooting MySQL Memory Usage
March 21, 2012 By 5 Comments
One of the most painful troubleshooting tasks with MySQL is troubleshooting memory usage. The problem usually starts like this – you have configured MySQL to use reasonable global buffers, such as innodb_buffer_size, key_buffer_size etc, you have reasonable amount of connections but yet MySQL takes much more memory than you would expect, causing swapping or other [...]
