MySQL – How much memory for InnoDB buffer?

Use this to find out how much storage each engine uses:

From the data above, it may seem like a good idea to keep innodb_buffer_pool low, because we have so much MyISAM data.
BUT if I get one query a minute against that MyISAM data, and 500 queries per second against the considerably smaller InnoDB data-set, that doesn’t make sense anymore.
Then we’d want all of the InnoDB data in memory, hence a buffer pool of 512M+

It’s down to data usage and where the hotspots are!

Percona Toolkit to ‘get the hotspots’

Get the hotspots:
you can set NUMPACKETS or keep the tcpdump running for 20 minutes. JUST keep an eye on the file size!

FYI:  official bug for that database being wrong thing