char vs varchar for performance in stock database

Question

I\'m using mySQL to set up a database of stock options. There are about 330,000 rows (each row is 1 option). I\'m new to SQL so I\'m trying to decide on the field types for

Answer 1

Also remember that creating databases is subject to whatever actual database implementation you use. If you ever port from MySQL to, say, Postgresql, you will discover a very unpleasant fact that creating databases in postgresql is a comparatively very slow operation. It is orders of magnitude slower than reading and writing table rows, for instance.

It looks like there is an application design problem to address first, before you optimize for performance choosing proper data types.