sql - Query optimization in this case -
i asking curiosity. stupid question or basic question. forgive me if is..
suppose have isthata table contains id, class, school_id having 1000 records.
there 3 schools , 12 classes.
which of these 2 queries faster(if there difference)
query 1: select * isthata school=2 , class=5; query 2: select * isthata class=5 , school=2;
note: changed places of 2 conditions in where
also probable number of records condition school=2 333
and probable number of records condition class=5 80.
there's no difference there. use explain select ...
discover approach mysql choose optimize , run queries. answer question.
Comments
Post a Comment