Home » Performance » MySQL » Two general MySQL questions..
Two general MySQL questions.. [message #522] Tue, 02 January 2007 10:17 Go to previous message
oordopjes  is currently offline oordopjes
Messages: 15
Registered: January 2007
Junior Member
Hi,

1. When using SQL_CALC_FOUND_ROWS combined with a LIMIT and an ORDER BY. Does MySQL stop ordering after the LIMIT is reached? Or are all results ordered by MySQL while getting the SQL_CALC_FOUND_ROWS?
If this is the case it probably is faster to do a SELECT COUNT(*) instead..without an ORDER BY.

2. When MySQL (regular INNER??) JOINs two tables.. Does it first do a SELECT on table1 and a SELECT on table2 and then combine the results? Or does it do a SELECT on table1, join it.. and do another select?

Thanks!

Read Message
Read Message
Read Message
Read Message
Read Message
Previous Topic:InnoDB tablespace inter-version compatibility
Next Topic:muti-key index order
Goto Forum:

  


Current Time: Sun Jul 5 16:04:18 EDT 2009

Total time taken to generate the page: 0.01137 seconds
.:: Contact :: Home ::.

Powered by: FUDforum 2.7.7.
Copyright ©2001-2007 FUD Forum Bulletin Board Software

MySQL is a trademark of Sun Microsystems.
InnoDB is a trademark of Oracle Corp.

Percona Performance Forums are a service of Percona, Inc.
Not affiliated with Sun Microsystems or Oracle Corp.