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RE: Locally managed tablespaces

From: Martin Kendall <Martin.Kendall_at_Rubus.com>
Date: Wed, 31 Jan 2001 07:43:09 -0800
Message-ID: <F001.002A5AA7.20010131072524@fatcity.com>

I have had a look at http://www.ixora.com.au/tips/creation/extents.htm but I am at a loss as to why the AUTOALLOCATE is "less efficient in terms of both space and algorithmic complexity than the UNIFORM SIZE policy".

Anyone care to comment. I am using LMTS is a Production envirnment without any probs at all.

Mart

-----Original Message-----
Sent: 30 January 2001 23:10
To: Multiple recipients of list ORACLE-L

Hi All,

I was working on a tuning assignment last week where one of the more minor changes made was to migrate their "scratch" tablespace to locally managed. The
gain from that change was about 2%. That saving was due to the elimination of ST
enqueue contention associated with multiple processes trying to create scratch
tables at the same time.

It is only certain data dictionary queries that are slower with locally managed
tablespaces, and that's only really bad if you have too many extents per segment. See http://www.ixora.com.au/tips/creation/extents.htm for why. The performance of SELECT and DML statements against user data is unchanged. The performance of space management transactions is slightly improved, and greatly
if ST enqueue contention was otherwise a problem.

@   Regards,
@   Steve Adams
@   http://www.ixora.com.au/
@   http://www.christianity.net.au/


-----Original Message-----
Sent: Wednesday, 31 January 2001 5:11
To: Multiple recipients of list ORACLE-L

Has anyone taken a PROD DB and changed it to using LMTSs and then noticed a perf
change + or -?

---

TheOracleDBA
theoracledba_at_lycos.com



On Tue, 30 Jan 2001 10:30:29
 Bunyamin K.Karadeniz wrote:

> But some had claimed that Locally managed tablespaces are slower. I do
>not know if it is correct but you must consider it .
> And I wonder the performance results too.
>
>----- Original Message -----
>To: Multiple recipients of list ORACLE-L <ORACLE-L_at_fatcity.com>
>Sent: Tuesday, January 30, 2001 3:35 PM
>
>
>> I have always been concerned with fragmentation of tablespaces, whether
it
>> be lots of extents, honeycomb or
>> bubble fragmentation. Now I am reading that in Oracle 8i with the use of
>> locally-managed table spaces,
>> these concerns are a thing of the past as Oracle now uses bit maps within
>> the tablespaces themselves to
>> do space management. This seems foreign to me that even though Oracle
will
>> use up all the space in
>> the tablespaces with no coalescing, it is OK that extents will go into
>the
>> thousands with no performance degradation.
>> Could folks who are currently using locally managed tablespaces please
>> comment on how well it
>> is working for them and if they have experienced any problems in using
>them.
>> Thanks
>> Skip
-- Please see the official ORACLE-L FAQ: http://www.orafaq.com -- Author: Steve Adams INET: steve.adams_at_ixora.com.au 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: Martin Kendall INET: Martin.Kendall_at_Rubus.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 Wed Jan 31 2001 - 09:43:09 CST

Original text of this message

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