Cache pre-loading on mysqld startup

The following quirky dynamic SQL will scan each index of each table so that they’re loaded into the key_buffer (MyISAM) or innodb_buffer_pool (InnoDB). If you also use the PBXT engine which does have a row cache but no clustered primary key, you could also incorporate some full table scans. To make mysqld execute this on […]

Trivia: identify this replication failure

We got good responses to the “identify this query profile” question. Indeed it indicates an SQL injection attack. Obviously a code problem, but you must also think about “what can we do right now to stop this”. See the responses and my last note on it below the original post. Got a new one for […]

Ladies and gentlemen, check your assumptions

I spent some time earlier this week trying to debug a permissions problem in Drupal. After a lot of head-scratching, it turned out that Drupal assumes that when you run INSERT queries sequentially on a table with an auto_increment integer column, the values that are assigned to this column will also be sequential, ie: 1, […]

Quiz: Enabling an application for MySQL Replication

A little challenge for you… given an existing app that does not know about separate master/slave connections, and you want to enable working in a replicated infrastructure.┬áSimply redirecting all SELECTs to the slave connection will not work. Why? Hint: there are at least two reasons, depending on other factors. There may be more. Comments are […]