Re: Sybase to Oracle Migration

There are many differences in terminolgy between Oracle and Sybase.

Think of an Oracle "database" as a catalog or "data dictionary". This the equivalent to Sybase's "master" plus all the system tables from each of the "user" databases.

The equivalant of a Sybase user database in Oracle is a schema.

Physical implimentation of storage is dramatically different:

Sybase uses raw partions which are fixed in size Oracle uses tablespaces (which can consist of many files) and may change size.

Tablespaces are becoming the defacto standard (Oracle, DB2, Informix and MS SQLServer V7 all use tablespaces).

Similar results, different terms and a different physical implimentation.

A few warnings:

You will also find significant differences in SQL DML and dramatic differences in stored procedures and triggers. This will affect the work effort to convert SQL from Sybase to Oracle. Also plan on increasing the DBA staff. A general rule of thumb is twice as many Oracle DBAs as Sybase DBA. So if you currently have 4 Sybase DBAs, plan on 6-8 Oracle DBAs. Here's an example: How many configuration parameters for Sybase ? a dozen ? (memory, procedure cashe %, number of cpus, open databases, open objects). Oracles parameters are in the hundreds which is good (you can tune everything) but requires a higher skill and training level.

Good Luck

Carl Federl
Director of Database Administration
USN Communications

Frank Tiemann wrote in message <6qseb5$hjs$1_at_hirame.wwa.com>...
>We are considering moving from Sybase to Oracle. However, we have a fairly
>large
>sized server (70+ GB), and the data is grouped logically in multiple
>databases within
>the Sybase server. My understanding is that Oracle does not allow more
 than
>one
>database per instance, is that correct? Would I then have to move all
 these
>tables
>(well over 1000) into one database?
>
>If anyone who has done Sybase to Oracle ports has any pointers, lists of
>migration issues
>(maybe even a whitepaper???) or a compare and contrast type chart, that
>would be fabulous
>and very helpful. Or, are there any good websites or books out there on
>that subject. I couldn't
>really find anything useful when searching the web.
>
>
>Thanks so much.
>
>Frank
>
>
Received on Fri Aug 14 1998 - 00:00:00 CDT