MySQL Forums
Forum List  »  Optimizer & Parser

Re: Subquery performance improvements: When?
Posted by: Olaf van der Spek
Date: February 14, 2006 08:31AM

xwi_logins: 5,799,457 rows
xwi_players: 189,252 rows

xwi_logins.sid is a key
xwi_players.pid is a unique key

Explain shows DEPENDENT SUBQUERY. Isn't the dependent part wrong?

select pid from xwi_logins where sid = 1139
757 rows in set (1.41 sec)
select distinct pid from xwi_logins where sid = 1139;
6 rows in set (0.01 sec)
select * from xwi_players where pid in (18146,34475,18154,53204,35060,18164);
6 rows in set (0.19 sec)



Edited 2 time(s). Last edit at 02/14/2006 08:33AM by Olaf van der Spek.

Options: ReplyQuote


Subject
Views
Written By
Posted
Re: Subquery performance improvements: When?
2415
February 14, 2006 08:31AM


Sorry, you can't reply to this topic. It has been closed.

Content reproduced on this site is the property of the respective copyright holders. It is not reviewed in advance by Oracle and does not necessarily represent the opinion of Oracle or any other party.