Re: Gotchas while migrating from DB2 to Oracle.

Hello,

You wrote earlier:

• Original Message ----- From: "Hemant Shah" <shah_at_typhoon.xnet.com> .>As I have said it and Joel also
  > suggested the application has worked without any problems for years and
  over
  > different data access method. Oracle is different so I have to code
  around
  > that. It would be a nightmare, if I redesign application everytime I have
  to
  > port to another data access method.
  

Unfortunately, the reality is such that Oracle is a fundamentally different beast from, say, DB2 with respect to transaction/concurrency mechanism. Oracle (as well as Postgres, Firebird/Interbase, etc) belong to a family of so-called multi-versioning schedulers whilst DB2, Informix, Microsoft SQL Server are locking schedulers. You would'nt've experienced such a shock if you'd ported between databases from the same 'family' since all the locking schedulers concurrency mechanisms are practically identical to each other.

In view of the above, I do not think you have much choice short of re-designing the application, at least the parts relying on the locking transaction scheduling, if Oracle is a must. Solid knowledge of the concurrency mechanism for both databases is a necessary pre-condition for the endeavour to succeed.

As to the web pages, this might be useful: http://otn.oracle.com/tech/migration/workbench/index.html

Good luck.

Rgds.

"Hemant Shah" <shah_at_typhoon.xnet.com> wrote in message news:br590p$12d$1_at_flood.xnet.com...
>
> Folks,
>
> I had posted article about changing isolation level in Oracle. That
thread
> was pretty lively. It seems Oracle will not block readers, and that
> difference (from DB2) has significant impact on our application.
>
> For people who has used DB2 and Oracle can you please tell me other
> differences you have found so that I can be prepared, or point me to a
> document/web page.
>
> We are porting our application from DB2 UDB (7.2) to Oracle 9i
(9.2.0.4.0).
>
> Thanks.
>
> --
> Hemant Shah /"\ ASCII ribbon campaign
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Received on Tue Dec 09 2003 - 14:03:37 CST