Re: PCTFREE & PCTUSED

From: Douglas Cowles <dcowles_at_us.ibm.com>
Date: 2000/03/15
Message-ID: <38CFBFC6.118C5DFC@us.ibm.com>#1/1

Actually according to the books
From Oracle Performance Tuning:
"PCTFREE: Percentage of space Oracle will leave in the current block when inserting a row into a table. .... Set PCTFREE to allow for row exapansion and it's associated chaining and migration..."

Next page:
"Most applications will perform optimally with a PCTFREE set high enough to avoid all chaining and migration, but..... PCTUSED value.. can also have an impact on performance... A high PCTUSED indicates data will be stored very efficiently in terms of space usage, but the liklihood of chaining and migration is increased."

So ideally, you want a high pctfree and a low pctused.

DNP wrote:

> I think you're getting PCTUSED and PCTFREE mixed up.
>
> David P.
Received on Wed Mar 15 2000 - 00:00:00 CST