RE: Coalescing Freespace / pctincrease = 1

From: Michael Ray <Michael.Ray_at_trw.com>
Date: Fri, 08 Dec 2000 05:46:28 -0800
Message-Id: <10704.124003@fatcity.com>

--=_FDA6FA79.93F29E3A

Content-Type: text/plain; charset=US-ASCII
Content-Transfer-Encoding: quoted-printable
Content-Disposition: inline

This is only true if the extent sizes in the TBS are not the same size. If = INITIAL=3DNEXT and all your objects use the TBS default, you should set = PCTINCREASE=3D0 so you do NOT automatically coalesce. That takes extra = overhead and the extents will always be reused anyway since they are the = same size throughout.

Michael Ray
Oracle DBA
TRW, Marshall, IL
217-826-3011 x2438

>>> pat.howe_at_Terabeam.com 12/07/00 09:33PM >>>

It is my understanding that in version 7.0 and later, the SMON background process automatically coalesces neighboring free extents if the default PCTINCREASE setting for the TABLESPACE is NON-ZERO. =20

If the default setting for the TABLESPACE is ZERO, then the free space in the tablespace will not be coalesced automatically by the database (SMON). You will have to do this manually.

Therefore in order for PMON to be able to AUTOMATICALLY colesce a = tablespace
the PCTFREE for the TABLESPACE must be > 0. Oracle recommends a default value of 1. =20

--=_FDA6FA79.93F29E3A
Content-Type: text/plain
Content-Disposition: attachment; filename="TEXT.htm"

<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN">
<HTML><HEAD>
<META content="text/html; charset=iso-8859-1" http-equiv=Content-Type>
<META content="MSHTML 5.00.2919.6307" name=GENERATOR></HEAD>
<BODY style="FONT: 8pt MS Sans Serif; MARGIN-LEFT: 2px; MARGIN-TOP: 2px">
<DIV>This is only true if the extent sizes in the TBS are not the same size. If
INITIAL=NEXT and all your objects use the TBS default, you should set PCTINCREASE=0 so you do NOT automatically coalesce. That takes extra overhead and the extents will always be reused anyway since they are the same size throughout.</DIV>
<DIV> </DIV>
<DIV>Michael Ray<BR>Oracle DBA<BR>TRW, Marshall, IL<BR>217-826-3011
x2438<BR><BR>>>> pat.howe_at_Terabeam.com 12/07/00 09:33PM >>><BR><BR>It is my understanding that in version 7.0 and later, the SMON background<BR>process automatically coalesces neighboring free extents if the default<BR>PCTINCREASE setting for the TABLESPACE is NON-ZERO. 
<BR><BR>If the default setting for the TABLESPACE is ZERO, then the free space
in<BR>the tablespace will not be coalesced automatically by the database (SMON).<BR>You will have to do this manually.<BR><BR>Therefore in order for PMON to be able to AUTOMATICALLY colesce a tablespace<BR>the PCTFREE for the TABLESPACE must be > 0.  Oracle recommends a default<BR>value of 1.  </DIV></BODY></HTML> Received on Fri Dec 08 2000 - 07:46:28 CST