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Home -> Community -> Mailing Lists -> Oracle-L -> RE: Tablespace management.
Jared,
It's rather simple. If you follow the rules of third normal form you have a table with a certain number of rows, a second with a certain number of rows for each row in the first table. Obviously the second table needs more space than the first. Now if you use Dictionary management you can set the storage parameters of each table individually. But if your using local management they both have the same extent sizes. This leads one to having the extent sizes smaller to accommodate the first table and large numbers of extents for the second table. True fragmentation, namely those small useless extents that land between larger used extents, is eliminated in local management but then I have not had those problems with dictionary management either, unless someone makes the case for moving a table but that's very rare.
Dick Goulet
Senior Oracle DBA
Oracle Certified 8i DBA
-----Original Message-----
Sent: Thursday, May 29, 2003 8:25 PM
To: ORACLE-L_at_fatcity.com
Cc: Goulet, Dick
Importance: High
Dick,
I'm trying to follow your line of thought, but I think I missed the path.
Objects may not have the same storage requirements, but what does that matter?
The only way I can make sense of what you say is if trying to have all
objects
occupy a single extent, and there's not much point in that.
Jared
"Goulet, Dick" <DGoulet_at_vicr.com>
Sent by: root_at_fatcity.com
05/29/2003 03:51 PM
Please respond to ORACLE-L
To: Multiple recipients of list ORACLE-L <ORACLE-L_at_fatcity.com>
cc:
Subject: RE: Tablespace management.
Thomas,
With the exception of temp and rollback tablespaces I
have not user locally managed tablespaces just because all objects must
have the same sized extents. I do not see most tables sharing an equal
need for storage and using dictionary management allows one to do that, at
a cost I'll admit, but one that is much easier to swallow.
Dick Goulet
Senior Oracle DBA
Oracle Certified 8i DBA
-----Original Message-----
Sent: Thursday, May 29, 2003 3:25 PM
To: Multiple recipients of list ORACLE-L
After reading the documents I've recommended using LOCAL, UNIFORM, AUTO as
the options for tablespace management. Does anyone have any bad
experiences with these? AUTOALLOCATE seems to come up with extents that
are much smaller than I want and MANUAL segment management requires the
use
of FREELISTs (and I know that there are problems with freelists freeing up
space correctly, especially in a parallel environment).
I can't find any basis for making a decision between UNDO and ROLLBACK SEGMENTS. Does anyone have any experience or recommendations about UNDO usage?
The database will be a materialize view replication of a transaction
master
that is being used for decision support and has a 15 minute update/refresh
cycle. Basically, people can run queries against the snapshot without
impacting the master.
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Author: Goulet, Dick
INET: DGoulet_at_vicr.com
Fat City Network Services -- 858-538-5051 http://www.fatcity.com San Diego, California -- Mailing list and web hosting services ---------------------------------------------------------------------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 Fri May 30 2003 - 08:49:51 CDT
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