mySQL primary index &amp; unique

mySQL primary index & unique

Anon

What means by index for a type say integer in mySQL?

Does primary imply unique?

Thanks,
William

Anon

its for searching...
if you will set a fields index, your selects in it (searches) will be more fast. its disadvantage is only to occupy some place. but in big databases (thousands of records) its not so important. your file will be some KB big but will be vary fast...

primary doesnt imply unique...