[nycphp-talk] MySQL doubt
mark at nostromo.net
Fri Jan 14 10:49:07 EST 2005
Sajith A wrote:
> I'm not sure whether i should post this here. Correct me if i'm
> wrong.. I would like to know
> whether there is any performance difference between. "SELECT count(*)
> FROM table" and "SELECT count(field) FROM table".
Mysql has different table types. MyISAM tables always know the number
of rows within the table. The result of "SELECT (*) from table" is
always known and should return instantly.
This may not work on other table types however. For instance, it does
not work for InnoDB tables.
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