Re: Fragmentation & Locally Managed Tablespaces

yep.

what I was wondering was at what point for storage in general, are the "points of inflection" for # of segments per tablespace, # of extents per segment - where a performance hit occurs, when the header block overflows.

I saw that a tablespace had > 34000 extents in it - but then saw that only 1 segment had > 505 extents - so I let it go.

just didn't want the extra I/O fetch every time.

Paul

Rachel Carmichael wrote:
>
> Mike,
>
> Thanks, I didn't really believe Oracle would "take back" the maxextents
> unlimited option, I just thought it was funny that the recommendation was
> now going back to the original extent recommendations :)
>
> Rachel
>
> >From: MHately_at_etech-uk.com
> >Reply-To: ORACLE-L_at_fatcity.com
> >To: Multiple recipients of list ORACLE-L <ORACLE-L_at_fatcity.com>
> >Subject: Re: Fragmentation & Locally Managed Tablespaces
> >Date: Thu, 28 Jun 2001 04:35:35 -0800
> >
> >
> >
> >Rachel,
> >That maximum isn't a hard limit. Oracle themselves impose no limit of this
> >kind.
> >After you use all of the available space in the segment header block, any
> >additional space map entries are overflowed into additional extent maps
> >within
> >the segment.
> >This means that because the used extent information isn't cached in the
> >data
> >dictionary, queries against dba_extents etc. can cause many blocks to be
> >read
> >from LMTs if the map entries have overflowed in this manner.
> >
> >Therefore, the limitation is more of a recommendation to ensure that good
> >performance is maintained.
> >
> >Regards,
> >Mike
> >
> >
> _________________________________________________________________
> Get your FREE download of MSN Explorer at http://explorer.msn.com
>
> --
> Please see the official ORACLE-L FAQ: http://www.orafaq.com
> --
> Author: Rachel Carmichael
> INET: carmichr_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).

-- 
Please see the official ORACLE-L FAQ: http://www.orafaq.com
-- 
Author: Paul Drake
  INET: paled_at_home.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).