3 ms·

Why? SELECT count(*) does not actually mean fetching all fields. It actually means fetching zero fields (the SQL standard is a bit weird) while SELECT count(uid

by jeltz 6y ago

Why? SELECT count(*) does not actually mean fetching all fields. It actually means fetching zero fields (the SQL standard is a bit weird) while SELECT count(uidpk) means fetching one field, but some databases optimize that to SELECT count(*) if uidpk is NOT NULL.