(I'm just posting this in case anyone is interested. I don't work for Oracle or MySQL, and I don't particularly care which RDBMS you use. At my work, we are using MySQL, and were before I got here because someone understood it was "industry standard".)
The other day I sat in on a Webinar, "Getting the Best MySQL Performance in Your Products, Part III, Query Tuning".
I picked up a few pointers, learned some stuff (I hope) that I was a tad fuzzy on before. Please keep in mind that I'm not a DBA,
and there's some question if I'm a Real Programmer(tm) at all
One thing that piqued my curiosity was the fact they were harping on MySQL 5.6, which I believe is in BETA. They claim some pretty
significant performance improvements since then. Of interest to some might be a new Performance_schema that helps with analysis of
performance issues, "semi-joins" and materialization (supporting subqueries in FROM, maybe? -if I'm understanding), auto-indexing of derived
tables, and faster filesorts/sort+limit.
Our projects have been, so far, run on MySQL 5.1. For a test, I ran a script that does a lot of DB munging, table creation, etc. It's supposed
to be an AI thing and was never tuned to run quickly; the hope was that it would, however, produce accurate guesses about what
a widget's function is, based on our system's previous knowledge of similar widgets.
A test run of this script generally takes just over an hour on my development box. For "fun", I deinstalled MySQL 5.1 and installed
5.5 --- and then ran the script again. It was done in 27 minutes.
Needless to say, I'm a little bit interested in getting some of our stuff into a newer MySQL Engine Real Soon Now(tm) ;-)