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Yelp IT! A talk with 3 Yelp MySQL DBAs on Percona Live & more

Founded in 2004 to help people find great local businesses, Yelp has some 135 million monthly unique visitors. With those traffic volumes Yelp’s 300+ engineers are constantly working to keep things moving smoothly – and …

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Faster restarts for MySQL and Percona Server 5.6.21+

By default in MySQL 5.6, each time MySQL is started (regular start or crash recovery), it iterates through all the binlog files when GTIDs are not enabled. This can take a very long time if …

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Comparing MongoDB, MySQL, and TokuMX Data Layout

A lot is said about the differences in the data between MySQL and MongoDB. Things such as “MongoDB is document based”, “MySQL is relational”, “InnoDB has a clustering key”, etc.. Some may wonder how TokuDB, …

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ORDER BY … LIMIT Performance Optimization

Suboptimal ORDER BY implementation, especially together with LIMIT is often the cause of MySQL Performance problems. Here is what you need to know about ORDER BY … LIMIT optimization to avoid these problems ORDER BY …

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A recovery trivia or how to recover from a lost ibdata1 file

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 …

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Using any general purpose computer as a special purpose SIMD computer

Often times, from a computing perspective, one must run a function on a large amount of input. Often times, the same function must be run on many pieces of input, and this is a very …

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Improved InnoDB rw_lock patch

There is patch from Google to improve SMP performance , but for some workloads it showed for us reverse scalability. E.g. update_key benchmark from sysbench. There are also results with Yasufumi’s rw_locks (http://bugs.mysql.com/bug.php?id=26442)

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To pack or not to pack – MyISAM Key compression

MyISAM storage engine has key compression which makes its indexes much smaller, allowing better fit in caches and so improving performance dramatically. Actually packed indexes not a bit longer rows is frequent reason of MyISAM …

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Descending indexing and loose index scan

Comments to my previous posts, especially this one by Gokhan inspired me to write a bit about descending indexes and about loose index scan, or what Gokhan calls “better range” support. None of these are …

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