I've had a lot of bad experiencing installing and managing the OEM grid control. Today has been the worst day ever and - as an alternative to self-mutilation - I decided that I would document my woes as they occur as a sort of therapy
At the MySQL Mini Conference in Sydney this week we discussed how to use EXPLAIN EXTENDED to view the rewrites undertaken by the MySQL optimizer. IN particular, to see if MySQL performs a merge of the query into the view definition, or if it creates a temporary table.
I wrote recently about using events and the new processlist table in MySQL 5.1 to keep track of the number of connected processes. Although having the PROCESSLIST available as an INFORMATION SCHEMA table is usefull, it seemed to me that having SHOW GLOBAL STATUS exposed in a similar fashion would be far more useful. So at the MySQL UC last year, I asked Brian Aker if that would be possible. I know how many enhancement requests MySQL has to deal with, so I was really happy to see that table appear in the latest 5.1 build (5.1.14 beta).
This table, together with the EVENT scheduler, lets us keep track of the values of status variables over time without having to have any external deamon running. This won't come anywhere near to matching what MySQL have made avalable in Merlin, but still could be fairly useful. So lets build a simple system using events to keep track of "interesting" status variables....