RE: Grow existing DBFs or add more?

Extents can't span datafiles. Each extent will be used across datafiles in round robin fashion.

Example: 1 tablespace, 2 files and one table with two extents. The first write is to extent one file one, the second write is to extent two file two, then back to one and so on. Possibility exists that the first file has more extents based on initial extent allocation, but I didn't test this out.

This is light on the technical, but it might help.

Personally, I'd use fewer, larger files, but that point is based on the arbitrary nature of the installation, meaning fewer larger files work in some cases, and not in others. I'd prefer to go ASM bigfile on everything and not worry about storage allocation, but no luck with that yet.

-T

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

From: oracle-l-bounce_at_freelists.org [mailto:oracle-l-bounce_at_freelists.org] On Behalf Of Rich Jesse
Sent: Friday, August 10, 2007 12:07 PM
To: oracle-l_at_freelists.org
Subject: Grow existing DBFs or add more?

Hey all,

In 10.1.0.5, we're seeing unexpected growth in the data segment tablespace for JDEdwards. So I've been adding extra datafiles to accommodate -- no biggie. Looking into the future, I'm thinking that I'd like to increase the maxsize for the datafiles to mitigate checkpointing pressure.

With that in mind, is there any reason y'all can think of why I wouldn't want to increase the maxsize of the existing datafiles? We're using RMAN for backup and the physical layout is less-than-desirable sequentially striped luns on a RAID-5 SAN (before my time and before my SA's time, too), if that helps.

Nothing concrete comes to mind from net/doc searches nor memory, but something in the back of my head keeps nagging about the order in which extents are going to be spread across these datafiles and recovery.

TIA! Rich

--

http://www.freelists.org/webpage/oracle-l

--

http://www.freelists.org/webpage/oracle-l Received on Fri Aug 10 2007 - 15:19:35 CDT