Quite simple really, in a php/mysql set up, I have to run around 2M point updates on 25M items (where one update covers multiple primary keys), is there a way to pull this off with the same sort of gains as extended inserts?
I'm using unbuffered queries already. Its slow.
NB: Searching came up with nothing, this is on a dev environment so anything goes as there won't be this issue in prod.. yay for real servers.
Have you tried prepared statements?
The query only needs to be parsed (or prepared) once, but can be executed multiple times with the same or different parameters. [...] By using a prepared statement the application avoids repeating the analyze/compile/optimize cycle. This means that prepared statements use fewer resources and thus run faster.
One popular way to update a bunch of records is to create a new table, insert lots of records into that table (use extended inserts), and then swap out the old table with the new one.