Sign Up to our social questions and Answers Engine to ask questions, answer people’s questions, and connect with other people.
Login to our social questions & Answers Engine to ask questions answer people’s questions & connect with other people.
Lost your password? Please enter your email address. You will receive a link and will create a new password via email.
Please briefly explain why you feel this question should be reported.
Please briefly explain why you feel this answer should be reported.
Please briefly explain why you feel this user should be reported.
I have two tables (MYISAM)
create table A (email varchar(50));
create table B( email varchar(50) key 'email' (email));
Table A has 130K records
Table B has 20K records
why does this sql statement take very long time (more than two minutes, then i aborted query by Ctrl+C)
Statement is:
select count(*) from user A, tmp B where A.email=B.email;
Thanks
I’d guess that the Query optimizer has nothing to go on. Why don’t you try defining indexes on the email columns.