Twenty Instances? At 500M per SGA, you're talking a minimum of 12+ G of
RAM. How many users per instance? More RAM. Are these OLTP or
Datawarehousing type DBs? Disk and I/O and RAM. 24 x 7? If one has to
be, then you're going to need some type of failover/standby capability.
What vendor
You also have to consider the OS overhead.
Putting 20 instances means hundreds of processes.
Just managing all this at the system level can be resource consuming.
Yechiel Adar
Mehish
- Original Message -
To: Multiple recipients of list ORACLE-L [EMAIL PROTECTED]
Sent: Friday, August 02,
I would recommend a Sun E-15k. The best option would be to domain it into
separate virtual boxes so that each instance has it's own space. Or, you
could go the other route and buy a bunch of Ultra-2 machines and give each
database its own box. Or, maybe a blade for each instance?
Thanks for the comments, all were good and James makes some good points
(your right up the road from me by the way). I personally like the blade
systems. I have only seen Egenera's Linux based system but I guess HP and
others have some systems out. How does the cost on these systems look?
Ethan - Now that you have clarified the reason why you want 20 instances,
I'll change my advice and say that in your situation, 20 instances may be
the better choice. Two other factors you need to consider:
1. An ASP is a lot like the old time-sharing systems. You must have an
absolutely
2002
Date: Thu, 01 Aug 2002 18:23:21 -0800
To: Multiple recipients of list ORACLE-L [EMAIL PROTECTED]
X-Comment: Oracle RDBMS Community Forum
X-Sender: James J. Morrow [EMAIL PROTECTED]
From: James J. Morrow [EMAIL PROTECTED]
Subject: Re: 20 Instances 1 Machine
X-ListServer: v1.0g, build 71
Good point Dennis - version issues. We create a separate Oracle home for each 3rd
party application that we install at our company for this very reason.
Jay
[EMAIL PROTECTED] 08/02/02 01:05PM
Ethan - Now that you have clarified the reason why you want 20 instances,
I'll change my advice and
I am going to reply to this myself before I get flamed. I found a recent
discussion on usenet regarding this topic.
http://groups.google.com/groups?hl=enlr=ie=UTF-8oe=UTF-8threadm=3d1091af
%240%2428006%24afc38c87%40news.optusnet.com.aurnum=15prev=/groups%3Fq%3Dto
Ethan - Technically it shouldn't be a problem. Which Unix? What is the
objective of 20 instances rather than one instance with 20 schemas? A single
instance allows Oracle to allocate resources more efficiently. For example,
the data buffer reflects the hottest blocks globally, rather than 20
Ethan,
The points you make are valid. There will be some resource wastage
due to the overhead of each instance and database, but the potential
downside may make it worthwhile. Suppose customerA's application has a bug
generates a ton of redo, overflowing the archive_dump_dest. This means
expressly stated otherwise.
Fink, Dan [EMAIL PROTECTED]
Sent by: [EMAIL PROTECTED]
02-08-2002 09:13 AM
Please respond to ORACLE-L
To: Multiple recipients of list ORACLE-L [EMAIL PROTECTED]
cc:
Fax to:
Subject:RE: 20 Instances 1 Machine
Ethan
Your biggest problem is not going to be physical RAM or disk space (either of
those could simply be purchased large enough). However, you *will* encounter a
problem with Shared Memory.
32-bit (and even 64-bit) operating systems have a finite amount of shared
memory addressable for use by
I have not heard about such limitation for shared memory size on Solaris.
Even if such limitation exists it will be on the process level.
This means 2GB or 4GB for each database instance.
Regards,
Waleed
-Original Message-
To: Multiple recipients of list ORACLE-L
Sent: 8/1/02
James J. Morrow£¬
if you're running a 32-bit version of Oracle, this number represents the sum of
all SGA's running on that machine at the time. (So, at 500M/instance, you'll
run out somewhere between 3 and 4 instances).
hi, i believe that you are wrong on this topic. Yes, 32bit
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