Monthly Archives: November 2011

MySQL – WordPress & Avoiding unneeded Group By clauses

A client recently reached out in regard to a reproducible performance problem on their WordPress site.  The use case and conditions were as follows: Performance was fine until a change happened to the wp_posts or wp_term_relationships tables (i.e. when a … Continue reading

Posted in Database, Performance | 1 Comment

MySQL – inner join vs. exists() may yield better performance

Here’s another example of why it’s always a good idea to refer to execution plans and test different query options.  Here’s a query I was running as part of some manual data work: SELECT ua.* FROM vn_user_achievements ua WHERE EXISTS … Continue reading

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MySQL – Got error 28 from storage engine

Just after a late night deployment I received this error message while running queries against the production database I just deployed to: Got error 28 from storage engine query I could connect to the database fine, but any database query … Continue reading

Posted in Database | 3 Comments