Hi Toon, In a nutshell.. You can have as many oracle databases/oracle_home's as you want on windows 2003. No limits, same as Unix/Linux Each running database is a single multithreaded windows process (oracle.exe) Each database has an associated windows service so that's how you manage automatic startup after a boot "Dos box" sqlplus is my own favourite SQL CLI because of command history. As for HA, next to RAC and Dataguard there's also Failsafe, based on MSCS. Andre Van: oracle-l-bounce@xxxxxxxxxxxxx [mailto:oracle-l-bounce@xxxxxxxxxxxxx] Namens Toon Koppelaars Verzonden: maandag 25 januari 2010 17:30 Aan: oracle-l-freelists Onderwerp: Multiple production databases (and/or oracle_homes) on one windows server Hi, Context: 11Gr1, Windows Server 2003 I'm curious if this (see subject) is done at all. My background is primarily using Unix/Linux as the OS for a database server. And I see how having multiple production databases, supported by a single, or even multiple oracle_homes, is not an issue on Unix/Linux. Given that there is enough memory + cpu to service the instances. But how is this in the Windows space? Should I go there? Or stay far away from it? Any comments are appreciated. Toon -- Toon Koppelaars RuleGen BV <mailto:Toon.Koppelaars@xxxxxxxxxxx> Toon.Koppelaars@xxxxxxxxxxx <http://www.RuleGen.com> www.RuleGen.com <http://TheHelsinkiDeclaration.blogspot.com> TheHelsinkiDeclaration.blogspot.com (co)Author: "Applied Mathematics for Database Professionals" <http://www.RuleGen.com/pls/apex/f?p=14265:13> www.RuleGen.com/pls/apex/f?p=14265:13