Question

I’ve a field of type char(1) in my MySQL table which basically can have only values m or f. Its current collation is set to ut8_unicode_ci. I was thinking whether I should or should not change the collation to something simpler like latin because the full set of utf8 chars is never used – only the chars m or f. Would that change something?

Answer 1

I doubt that it will make any measurable difference, but if m and f are the only possible values, then utf8_bin should produce exactly the same results as utf8_unicode_ci (or most other collation algorithms for that matter). And since that collation does a simple binary comparison it’s bound to be the fastest one around.