hi,
i am using count() query and having question on performance: is there a difference between using
count(*) and count(<columnName>)? * would select all columns whereas count(<column>) only selects one particular column, so i would guess that the latter is faster (a table with less column entries needs to be created before running count()).
i ran some
test scripts and count(<columnName>) seems to faster, but i wouldn't bet on it for i don't know caching and internal tweaking strategies of the server. i also think it is dbms-server product specific.
so can one generally say that count(<columnName>) is faster?