Re: Oracle PCTUSED/PCTFREE settings

From: Martin J. Malley <mmalley_at_radiks.net>
Date: 1997/09/05
Message-ID: <01bcb990$add9e9e0$8f4303cf@gateway>#1/1

> I'm a little confused in determining the optimal value for PCTUSED.
> I understand the principle, but well-known documentation
> (Oracle DBA manual, Oracle Design by O'Reilly) contradicts each other.
> I am inclined to set PCTUSED to zero, instead of leaving it at the
> default > of 40.
> WHy does it matter how many deletes/updates i do? Is it okay
> to bring a block off of the free list when the block is empty?

It only matters if you care about disk space and the number of blocks that need to be scanned in a full table scan. If you set pctused at zero, and have significant delete activity, it is unlikely you will ever reclaim many blocks. Therefore the table will be growing and wasting disk space.

If you have a lot of deletes, set pctused higher to more efficiently use the disk blocks your table consumes. Received on Fri Sep 05 1997 - 00:00:00 CDT