Multiple database on one instance

Hi !

Could anyone tell me how to run multiple databases connected to one single Instance. Is it possible ?
Could anyone please explain if so.

No it is not possible, but you can create two database with corresponding instance each.

Hi reydp..

let's say you wanted 2 different instances on one server.

Would that mean that you would have to install oracle software for each instance on the server with 2 oracle_homes?

I take it you would be able to start both instances simultaneously and access either one depending on oracle_sid value in .profile (unix), or service name in tnsnames for NT.

Can you please clarify as I have never needed to set up such a scenario and would like to know how it's done.

Can you also clarify whether it is possible to connect to either service on a unix box without having to set oracle_sid, but specifying service name as part of connect string ?

eg
conn system/manager@service1
conn system/manager@service2

Thanks in advance

Suresh

you can do it in the other way round

in NT not sure, there is a Note on Metalink explain how to setup OPS in single Node

hi sureshy,


----------------------------------------------------
let's say you wanted 2 different instances on one server.

Would that mean that you would have to install oracle software for each instance on the server with 2 oracle_homes?
----------------------------------------------------
No, you don't have to, but it still possible if other version is necessary.

To create another database with the same server is:
above all, shutdown the original db and backup
1. copy and rename the original initSID.ora(newinitSID.ora)
change the directories for control file and archive log files.
change the db_name(NEW_DB).
2. source the ORACLE_SID=NEW_DB
3. startup nomount pfile=newinitSID.ora
4. issue the command to create the new database the usual.
create database "NEW_DB"
DATAFILE .... SIZE 300MB
LOGFILE GROUP 1.....
GROUP 2....
MAXDATAFILES 1024
MAXLOGFILES 248
blah....blah....
5. run catalog.sql and catproc.sql
6. your db must be ready to open.

Add tnsnames for the new database, and same as for listener

then you can connect
system/manager@oldtnsname
and
system/manager@newtnsname

without sourcing the ORACLE_SID.

I hope I don't miss something.

Hi Reydp

Thanks for the reply.. very helpful.

Suresh

if it is OPS multiple instances access a single database.
if you want multiple databases under multiple oracle homes it is possible. this is possible by taking care of listener entries and tnsnames entries on unix or win nt/2000 systems.