Re: Multiple database in one instance

Barbara.

This is correct. I am running Personal Oracle 8i for Windows 98, so I have a problem with developing multiple applications each with its own schema or application table relational structure of you like. I create a separate TABLESPACE for each schema (application) which has its own unique OWNER (user). This solves the problem if a table in one schema has the same name for a table in another, as it is prefixed by the OWNER/SCHEMA name.

For example the EMPLOYEE table in the IWP_DATA Tablespace/Schema is called IWP_OWNER.EMPLOYEE whereas it is called PAYROLL.EMPLOYEE in the PAYROLL Tablespace/Schema.

TableSpace                 Owner                             Schema
                                  (default tablespace)
--------------------------------------------------------------------------
TRAVEL                  TRAVEL                           TRAVEL
IWP_DATA             IWP_OWNER                   IWP_OWNER
ACCOUNTS           ACCT                                ACCT
DEMO                     DEMO                               DEMO
PAYROLL               PAYROLL                        PAYROLL

I have been working with various RDBMS and application development for 23 years and there is a little confusion if you are coming into Oracle from other platforms as I am currently attempting. There is an additional level in the concept structure to identify.

The "Instance" is the complex set of memory structures, background and operating system processes. The instance structure is based on the multitasking implementation in UNIX. Processes have specific tasks within the RDBMS that work together, and each process has its own memory block to store variables address stacks etc. The Instance is sort of like the Server Manager in MS SQL Server.

The "Database" pertains to the database files, control files and redo logs part of the RDBMS.

The "Schema" describes the properties of the database files. There is also of course the schema owner and users that have permission to access that schema.

Regards
Peter Luxmore

Barbara Kennedy wrote:

> Just have multiple schemas. For all intents and purposes it is a multiple
> database to you.
> Jim
> <woods_john_at_crane.navy.mil> wrote in message
> news:8nrnpb$q6o$1_at_nnrp1.deja.com...
> > Is it possible to have more than one database per instance. If so, how?
> >
> > Thanks,
> >
> > John Woods
> >
> >
> > Sent via Deja.com http://www.deja.com/
> > Before you buy.
Received on Wed Aug 30 2000 - 06:54:26 CDT