Almost every time I start a new project I Google this same question to see if I come up with any new answers.
It eventually boils down to - I take the latest version of MySQL and run tests.
I have tables where I want to do key/value lookups... and that's all. I need to get the value (0-512 bytes) for a hash key. There is not a lot of transactions on this DB. The table gets updates occasionally (in it's entirety), but 0 transactions.
So we're not talking about a complex system here, we are talking about a simple lookup,.. and how (other than making the table RAM resident) we can optimize performance.
I also do tests on other databases (ie NoSQL) to see if there is anywhere I can get an advantage. The biggest advantage I have found is in key mapping but as far as the lookup goes, MyISAM is currently topping them all.
Albeit, I wouldn't perform financial transactions with MyISAM tables but for simple lookups, you should test it out.. typically 2x to 5x the queries/sec.
Test it, I welcome debate.
