RE: separate tablespaces for tables and indexes

All,

All of your arguments about "indexes and their tables were read serially anyway", to me, only really holds up when, as you say, there is only one user on the machine.

But we know that this test case *never* happens. There are always multiple users on the database. So splitting IO's via separation of index and data was still a great idea at the time. It was certainly better than having everything on one big disk.

But now, I'm just not sure what the correct answer is. To me, it all comes back to object management. If the disk/SAN farm is/are big and fast enough, then I don't have to worry about contention and disk throughput anymore. (This is actually what I'm dealing with now. We use both EMC and IBM Shark arrays. I have no freekin idea how the physical disk are mounted and used by the applications. I only know I have mount points on the unix box that I create my files on).

So I vote for keeping things separate for management purposes. But I get the feeling that with auto segment management that this may not matter anymore in a few years.

Tom

-----Original Message-----

From: Mercadante, Thomas F [mailto:thomas.mercadante_at_labor.state.ny.us] Sent: Monday, December 13, 2004 2:15 PM
To: 'JBECKSTROM_at_gcrta.org'; oracle-l_at_freelists.org Subject: RE: separate tablespaces for tables and indexes

Jeff,

In my view, separating indexes and tables was never about tablespace contention. It was always about moving the index and table files onto separate disk drives to avoid disk contention.

Now that we have SAN disk where the 10 mount points that we see on a Unix box are actually split from the 3 hard disk drives on the SAN box, I'm not sure that splitting indexes and tables for performance matter anymore.

If you are going to use automatic allocation of segments for the database objects, it would be interesting to hear from the experts if the separation of these objects really matters.

However, I still do it for management of database objects - mostly because index segment usage is so much smaller that table segment usage.

Hope this helps.

Tom

-----Original Message-----

From: Jeffrey Beckstrom [mailto:JBECKSTROM_at_gcrta.org] Sent: Monday, December 13, 2004 2:05 PM
To: oracle-l_at_freelists.org; ORACLE-L_at_IC.SUNYSB.EDU; oracledba_at_LazyDBA.com; oracle-rdbms_at_yahoogroups.com
Subject: separate tablespaces for tables and indexes

We have started using locally managed tablespaces for all new tablespaces. We create the tablespaces with autoallocate.  

Since the tablespaces are locally managed, is there a need to separate the tables and indexes anymore?    

Jeffrey Beckstrom
Database Administrator
Greater Cleveland Regional Transit Authority 1240 W. 6th Street
Cleveland, Ohio 44113

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http://www.freelists.org/webpage/oracle-l Received on Mon Dec 13 2004 - 13:39:41 CST