Re: Migration from Informix to Oracle 7.3.3

Joel Garry <joelga_at_pebble.ml.org> wrote:
> >install it anyway.) It seems that oracle can only serve a single database
> >per instance. This means we would have to run 60+ instances of oracle on
> >the DB server, does it not? Many of the databases have identical tables
> >and are archive versions of the main database. I.e. the Fall Semester
> >1996 student database.
 

> It's hard to say from the amount of information given, but I think we
> have a terminology problem here. I think what Informix is calling a
> "database" Oracle calls a "schema." Database may be a much more
> all-encompassing concept in Oracle.

In Informix, you have a number of different databases on the same server.

Each database has it's own unique set of tables.

We have typically granted access based on a whole database. If you are able to 'connect' to a given database, that it usually sufficient to get you access to the tables.

More importantly, one particular user may own tables in more than one database. As near as I can tell, the closest concept to the 'database $databasename' statement in oracle would be connecting to a given instance. Unfortunately, creating 45 instances would hardly be reasonable, and would be a major memory hog.

> >Oracle does not seem to support .rhosts/hosts.equiv authentication, so it
> >looks like we'll have to move to embedding the passwords in the perl
> >scripts that connect to the database server (or in a local file or similar).
 

> Without knowing exactly what you are doing, I'd say you might want to look
> into the OS_AUTHENT_PREFIX capability for Oracle to use the operating system
> to control logins.

Informix's network connections use either 'userid & password' or BSD/rhosts/hosts.equiv mechanism to authenticate the user. This means that if you have a set a unix hosts in a workgroup, you can just add them all to hosts.equiv, and each can access the database server as if they were a local login.

With Oracle, it looks like I can get authenticated without a password IF I do the OS authenticated logins BUT only on the database server itself. They clearly state in the manual that there is NO security if you enable that and remote os authentication.

As we don't consider it acceptable to run applications directly on the database server, we're going to wind up embedding userid and password in our code or in a local file on each host.

• Nathan

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Nathan Neulinger                       EMail:  nneul_at_umr.edu
University of Missouri - Rolla         Phone: (573) 341-4841
Computing Services                       Fax: (573) 341-4216