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Search Results for: query to find locked tables in mysql

Interactive Debugging of Transaction Conflicts with TokuDB

I am developing a concurrent application that uses TokuDB to store its database. Sometimes, one of my SQL statements returns with a ‘lock wait timeout exceeded’ error. How do I identify the cause of this …

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A TokuDB Stall Caused by Conflicting Transactions When Opening a Table

One of our customers reported that ‘create table select from’ statements stall for a period of time equal to the TokuDB lock timeout.  This indicated a lock conflict between multiple transactions.  In addition, other MySQL …

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Hot Column Addition and Deletion Part I – Performance

From 18 hours to 3 seconds! Hot Column Addition and Deletion (HCAD) Overview TokuDB v5.0 introduces several features that are new to the MySQL world. In this series of posts, we’re going to present some …

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The perils of InnoDB with Debian and startup scripts

Are you running MySQL on Debian or Ubuntu with InnoDB? You might want to disable /etc/mysql/debian-start. When you run /etc/init.d/mysql start it runs this script, which runs mysqlcheck, which can destroy performance. It can happen …

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SHOW INNODB STATUS walk through

Many people asked me to publish a walk through SHOW INNODB STATUS output, showing what you can learn from SHOW INNODB STATUS output and how to use this info to improve MySQL Performance. To start …

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