Tag: performance

  • Don’t forget to defragment /home if you’re using BTRFS

    don’t forget to defragment a btrfs filesystem … large (sqlite database like files etc) will fragment and become slow

  • MySQL update/write query analysis (query profiling)

    Do you have a slow MySQL update/insert/delete query? Obviously, for ‘SELECT’ queries you can prepend the query with “EXPLAIN ” – however that doesn’t work for the other query types (UPDATE/INSERT/DELETE). So, one solution which may explain why the query is slow is to turn on MySQL’s profiling functionality, like in the following example :

  • Zend_Cache – automatic cache cleaning can be bad, mmkay?

    $customer uses Zend_Cache in their codebase – and I noticed that every so often a page request would take ~5 seeconds (for no apparent reason), while normally they take < 1 second … Some rummaging and profiling with xdebug showed that some requests looked like : Note how there are 25,000 or so calls for…

  • Late to the performance party

    Everyone else probably already knows this, but $project is/was doing two queries on the MySQL database every time the end user typed in something to search on to get the data between a set range (SELECT x,y….. LIMIT n, OFFSET m or whatever) and another to get the total count of records (SELECT count(field) ….).…