| Oracle FAQ | Your Portal to the Oracle Knowledge Grid | |
 |
 | |||
| Oracle FAQ | Your Portal to the Oracle Knowledge Grid | |
|
| |||
Home -> Community -> Mailing Lists -> Oracle-L -> Re: PCTUSED??
Greg
My concern is How can I reuse the deleted space, I have 20Gb Table with 15Gb Indexes, So I may not touch the table due to massiveness, I can do atleast indexes rebuild for availing 3-4Gb back. So in that regard pct_used has greater significance for reusing the space for future insertions.
Thank you all for your responses and valueble input.
Thanks
Raghu.
>From: Greg Moore <sqlgreg_at_pacbell.net>
>Reply-To: ORACLE-L_at_fatcity.com
>To: Multiple recipients of list ORACLE-L <ORACLE-L_at_fatcity.com>
>Subject: Re: PCTUSED??
>Date: Wed, 06 Jun 2001 15:56:25 -0800
>
> > I have big growing tables has default PCT_USED 40%, But we delete data
>some
> > times one year or 2yrs data. What is optimum value for this parameter??
>I
> > may consider my database is oltp. So how can decide a correct value for
> > this???
>
>PCT_USED might not have any effect for you at all.
>
>If you keep inserting rows by date, the blocks will fill with rows where
>the
>date is the same for every row in the block, or close. Then if the only
>time you delete is when you delete an entire year's worth of data, entire
>blocks will become empty. That's going to cause them to go on the free
>list
>no matter what you set PCT_USED to.
>
>As the other reply implied, your main concern may be tables where, after
>the
>mass deletes, there are many blocks below the high water mark that are
>completely empty. This would take up a little disk space until they are
>filled, but the main concern would be that full table scans would take as
>long after the deletes as before, due to the need to read all blocks up to
>the high water mark (empty or full). So if that is a concern you could
>reorg the table.
>
>--
>Please see the official ORACLE-L FAQ: http://www.orafaq.com
>--
>Author: Greg Moore
> INET: sqlgreg_at_pacbell.net
>
>Fat City Network Services -- (858) 538-5051 FAX: (858) 538-5051
>San Diego, California -- Public Internet access / Mailing Lists
>--------------------------------------------------------------------
>To REMOVE yourself from this mailing list, send an E-Mail message
>to: ListGuru_at_fatcity.com (note EXACT spelling of 'ListGuru') and in
>the message BODY, include a line containing: UNSUB ORACLE-L
>(or the name of mailing list you want to be removed from). You may
>also send the HELP command for other information (like subscribing).
-- Please see the official ORACLE-L FAQ: http://www.orafaq.com -- Author: Raghu Kota INET: raghukota_at_hotmail.com Fat City Network Services -- (858) 538-5051 FAX: (858) 538-5051 San Diego, California -- Public Internet access / Mailing Lists -------------------------------------------------------------------- To REMOVE yourself from this mailing list, send an E-Mail message to: ListGuru_at_fatcity.com (note EXACT spelling of 'ListGuru') and in the message BODY, include a line containing: UNSUB ORACLE-L (or the name of mailing list you want to be removed from). You may also send the HELP command for other information (like subscribing).Received on Thu Jun 07 2001 - 09:26:30 CDT
 |
 |