Hemant Dick makes a good point about physical memory. The problem with a lot of instances is that they all have fixed amounts of memory (except in 9i, up to SGA_MAX_SIZE), and if one instance needs more memory you can't reallocate unless you bounce it to add memory and maybe bounce several others to reduce their memory. If you can consolidate instances, then they will be dynamically sharing memory. Probably not the answer management wants to hear, though.
Dennis Williams DBA, 40%OCP, 100% DBA Lifetouch, Inc. [EMAIL PROTECTED] -----Original Message----- Sent: Tuesday, March 11, 2003 8:50 AM To: Multiple recipients of list ORACLE-L We also run several instances on just about every server we have. Most, but not all share the same Oracle_home. I only create new ones for newer versions of Oracle, but for each database I prefer to use seperate mount points such as: /test/system /test/rbs /test/temp /prod1/system /prod1/rbs /prod1/temp /prod2/system etc....... Keeps one from stepping on one's own _________. (You fill in the blanks.) The biggest problem I think you'll face is physical memory. Have too little with too big an SGA & you start swapping. Have smaller SGA's and wait IO can become a problem. Simply put, you just can't have too much memory. Typically we license a server for whatever it's being used for, so yes we do have user and cpu licenses. Kind of a pain keeping track. Dick Goulet ____________________Reply Separator____________________ Author: "Stephane Paquette" <[EMAIL PROTECTED]> Date: 3/11/2003 6:19 AM Hi, On one of the 7 development box (aix 4.3.3) we have 27 instances Oracle 8172. All using the same oracle_home. I can't say it's the fastest response time ;-) As for the licensing we have a mix of CPU and user licences. Stephane Paquette Administrateur de bases de donnees Database Administrator Standard Life www.standardlife.ca Tél. (514) 925-7187 [EMAIL PROTECTED] <mailto:[EMAIL PROTECTED]> -----Original Message----- Chitale Sent: Tuesday, March 11, 2003 3:49 AM To: Multiple recipients of list ORACLE-L One of the teams here is planning to run anything from 8 to 16 database instances [no indication on sizing yet, but gut-feel SGAs are 200MB to 1GB and DB sizes 500MB to 40GB] on a "large" server, something like a Sun E6800 or an equivalent HP or Fujitsu server. 1. How many of you do run, and are comfortable running, multiple databases on the same server, whether it is "partitioned" or not ? 2. Do you create a seperate ORACLE_HOME for each instance ? 3. Do you just buy the Oracle DB CPU license on the total number of CPUs on the server ? My positioning is a. We might not be able to create 8 partitions but partition such that we have a max of 2 or 3 instances in one partition. Hopefully, I can dynamically change CPU partitioning to reallocate CPU to another group of instances. b. Each instance should have it's own ORACLE_HOME. [Disk space is not a constraint]. c. Just add up the number of CPUs on the server, across all partitions, and buy a CPU license. Also, a CPU license is much preferable to Named-User as some of these databases would host Portals for 1,000+ end-users. Hemant K Chitale http://hkchital.tripod.com -- Please see the official ORACLE-L FAQ: http://www.orafaq.net -- Author: Hemant K Chitale INET: [EMAIL PROTECTED] 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: [EMAIL PROTECTED] (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). -- Please see the official ORACLE-L FAQ: http://www.orafaq.net -- Author: Stephane Paquette INET: [EMAIL PROTECTED] 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: [EMAIL PROTECTED] (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). -- Please see the official ORACLE-L FAQ: http://www.orafaq.net -- Author: INET: [EMAIL PROTECTED] 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: [EMAIL PROTECTED] (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). -- Please see the official ORACLE-L FAQ: http://www.orafaq.net -- Author: DENNIS WILLIAMS INET: [EMAIL PROTECTED] 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: [EMAIL PROTECTED] (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).