Re: DB File Sequential Read Waits

There are three things I can think of that might help:

1. Find queries where the number of disk reads is significantly higher than the number of rows returned, and check to see if the tkprof output shows the table returning far fewer rows than the index, where the disk figure in the tkprof output is roughly the same as the INDEX line rows. This indicates lots of table blocks being visited unnecessarily, and MIGHT be fixed by adding columns to indexes to avoid the excess table visits.

Jonathan,

You mention checking disk reads.

Do you subscribe to the notion that one should only tune to reduce logical I/O? Received on Sun Jan 04 2004 - 11:37:01 CST