Re: 2GB or not 2GB (datafile limit)? That is the question.

As I said, there wasn't detailed analysis of the situation, but the SysAdmin thought that might be the case. It was on an HPUX server connected to an older HP XP512 SAN, which consists of about fourteen 72GB RAID5 LUNS. That's the way it was set up 5 years ago and that's what we're stuck with.

Our server group buys SANs, gets the vendor (now IBM) to configure them for file storage, then tells us that they're out there. I've given up trying to convince them to include us early on. Anyway, we have terabytes and terabytes of SAN, of which our Oracle databases get plenty, so I can't complain too much. Also, all the Opteron machines we're getting for database servers are pretty nice, too.

So, I'll retract my assertion, since I don't really know and don't want to start any kind of Oracle Myth. The 2GB datafile size is still handy for all the other reasons I mentioned.

Jack C. Applewhite - Database Administrator Austin (Texas) Independent School District 512.414.9715 (wk) / 512.935.5929 (pager)

 I feel so unnecessary. -- Rufus Thomas

               ( "Do the Funky Chicken")

"Jared Still" <jkstill_at_gmail.com>
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Re: 2GB or not 2GB (datafile limit)? That is the question.

On 9/8/06, JApplewhite_at_austinisd.org <JApplewhite_at_austinisd.org > wrote:

Rich,

I don't know about OS issues, but we also stick to a max 2GB datafile size for a different reason. Almost all our servers (Linux and HPUX) are on one of our SANs and we've found that the OSs tend to give each mount point the same (on average) fraction of I/O bandwidth to the SANs. This was startlingly obvious when, at the recommendation of one of our SysAdmins, we put a Production database all under 1 mount point and its performance suffered greatly - no detailed analysis, it was just obvious. When we spread that same database across multiple mount points on the same server and SAN, performance improved dramatically.

That seems rather strange.

It likely had more to do with disk configuration rather than the number of mount points.

-- 
Jared Still 
Certifiable Oracle DBA and Part Time Perl Evangelist

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