I have been following Virident for a long time (e.g. http://www.mysqlperformanceblog.com/2010/06/15/virident-tachion-new-player-on-flash-pci-e-cards-market/). They have great PCIe Flash cards based on SLC NAND. I always thought that Virident needed to come up with an MLC card, and I am happy to see they have finally done so. At Virident’s request, I performed an evaluation of their MLC [...]
Infinite Replication Loop
October 10, 2011 By 2 Comments
Last week I helped 2 different customers with infinite replication loops. I decided to write a blog post about these infinite loop of binary log statements in MySQL Replication. To explain what they are, how to identify them… and how to fix them.
Dynamic row format for MEMORY tables
September 6, 2011 By 5 Comments
The latest Percona Server release has one new feature: now MEMORY tables can have BLOB and TEXT columns, and VARCHAR columns will not waste space due to implicit extension to CHAR.
Percona Server 5.1.58-12.9
August 17, 2011 By 2 Comments
Percona is glad to announce the release of Percona Server 5.1.58-12.9 on August 12, 2011 (Downloads are available here and from the Percona Software Repositories). Based on MySQL 5.1.58, including all the bug fixes in it, Percona Server 5.1.58-12.9 is now the current stable release in the 5.1 series. All of Percona’s software is open-source and free, all [...]
A recovery trivia or how to recover from a lost ibdata1 file
June 3, 2011 By 8 Comments
A few day ago, a customer came to Percona needing to recover data. Basically, while doing a transfer from one SAN to another, something went wrong and they lost the ibdata1 file, where all the table meta-data is stored. Fortunately, they were running with innodb_file_per_table so the data itself was available. What they could provide [...]
MySQL caching methods and tips
April 4, 2011 By 5 Comments
“The least expensive query is the query you never run.” Data access is expensive for your application. It often requires CPU, network and disk access, all of which can take a lot of time. Using less computing resources, particularly in the cloud, results in decreased overall operational costs, so caches provide real value by avoiding [...]
MySQL on Amazon RDS part 1: insert performance
March 15, 2011 By 37 Comments
Amazon’s Relational Database Service (RDS) is a cloud-hosted MySQL solution. I’ve had some clients hitting performance limitations on standard EC2 servers with EBS volumes (see SSD versus EBS death match), and one of them wanted to evaluate RDS as a replacement. It is built on the same technologies, but the hardware and networking are supposed [...]
Ultimate MySQL variable and status reference list
January 8, 2011 By 4 Comments
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 [...]
EXPLAIN EXTENDED can tell you all kinds of interesting things
June 15, 2010 By 7 Comments
While many people are familiar with the MySQL EXPLAIN command, fewer people are familiar with “extended explain” which was added in MySQL 4.1 EXPLAIN EXTENDED can show you what the MySQL optimizer does to your query. You might not know this, but MySQL can dramatically change your query before it actually executes it. This process [...]
A workaround for the performance problems of TEMPTABLE views
May 19, 2010 By 7 Comments
MySQL supports two different algorithms for views: the MERGE algorithm and the TEMPTABLE algorithm. These two algorithms differ greatly. A view which uses the MERGE algorithm can merge filter conditions into the view query itself. This has significant performance advantages over TEMPTABLE views. A view which uses the TEMPTABLE algorithm will have to compute the [...]
