Tag Archives: Tips

EXPLAIN EXTENDED can tell you all kinds of interesting things

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 …

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A workaround for the performance problems of TEMPTABLE views

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. …

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Debugging problems with row based replication

MySQL 5.1 introduces row based binary logging. In fact, the default binary logging format in GA versions of MySQL 5.1 is ‘MIXED’ STATEMENT*;   The binlog_format  variable can still be changed per sessions which means …

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fadvise – may be not what you expect

I often hear suggestion to use

system call to avoid caching in OS cache. We recently made patch for

, which supposes to create archive without polluting OS cache, as like in case with …

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Too many connections? No problem!

Did that ever happen to you in production?

Just happened to one of our customers. Want to know what we did?

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When should you store serialized objects in the database?

A while back Friendfeed posted a blog post explaining how they changed from storing data in MySQL columns to serializing data and just storing it inside TEXT/BLOB columns. It seems that since then, the technique …

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Getting around optimizer limitations with an IN() list

There was a discussion on LinkedIn one month ago that caught my eye: Database search by “within x number of miles” radius? Anyone out there created a zipcode database and created a “search within x …

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Effect of adaptive_flushing

I recently had the chance to witness the effects of innodb_adaptive_flushing on the performance of InnoDB Plugin 1.0.5 in the wild, which Yasufumi wrote about previously here and here. The server in question was Solaris …

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“Shard early, shard often”

I wrote a post a while back that said why you don’t want to shard.  In that post that I tried to explain that hardware advances such as 128G of RAM being so cheap is …

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Tokyo Tyrant -The Extras Part III : Write Bottleneck

This is part 3 of my Tyrant extra’s, part 1 focused on durability, part 2 focused on the perceived performance wall. #3.  Tokyo Cabinet Can have only a single writer thread, bottlenecking performance When writing …

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