mysql: am I doing something dumb with my indexing if my .MYI (index files) are bigger than my .MYD files?

Question

Is there ever a circumstance where the .MYI files should be bigger than my .MYD file?

I've got some pretty huge .MYI files and joins are running slowly. I'm pretty new to MySQL.

Database engine is MyISAM.

Answer 1

In my experience, .MYI files are often bigger than .MYD files, depending on the quantity and complexity of your indexes. Have you tried using explain to see if the right indexes are being used, or if you are using an inefficient select type in one of your joins (such as ALL)?

This manual page is a must for debugging slow queries