Migrating application from DB2 Z/OS

[jdokos]

Hello,

There is a project at my company to migrate a large, critical
application from DB2 Z/OS to either SQL Server or DB2 LUW. I would
assume that a migration from DB2 Z/OS to DB2 LUW would be less painful
and would require less data translation and data type mapping vs.
migration to SQL Server. Our vendor is telling us just the opposite.
In my opinion, they are saying this only because THEY are most
comfortable/knowledgeable about SQL Server.

Can anyone point me to documentation comparing such migrations? Or
showing that DB2 to DB2 migration should be easier?

TIA,
Jeff

[Helmut Tessarek]

Hi Jeff,

> Can anyone point me to documentation comparing such migrations? Or
> showing that DB2 to DB2 migration should be easier?

Since you are already DB2 customer, I would talk to your IBM representative.
He can organize a migration specialist who can answer all your questions in
more detail.

I can only tell you that SQL for z/OS and LUW is both adhering to the SQL
standard and that SQL for LUW is more powerful. This means that any SQL
statement you wrote for zOS will run on LUW.
The DDL on the other hand is a little bit different, because the concepts are
different (eg. data sets vs table spaces, ...), but it is definitely more
similar to LUW than to SQL Server DDL.

What about applications? What applications access the database and how? Static
SQL, Dynamic SQL, Cobol, Rexx, SAP? In any case, application migration will be
easier with LUW, since the interfaces are almost the same and the
communication is always DRDA.

There are many ways how you can do a migration. Offline, online, via unload
and load, via SQL or Q replication, load from cursor via federated db access.
Most things are also possible with SQL Server, but will be more complicated to
implement.

Application developers will be happy to know that locking strategy on DB2 LUW
is quite similar to z/OS (although page locking does not exist on LUW).

There are several Redbooks and white papers available. You can also find a
bunch of articles on developerWorks.

Maybe you want to check out the following 2 links for a start:

Moving Data Across the DB2 Family
http://www.redbooks.ibm.com/abstracts/sg246905.html

The SQL Reference for Cross-Platform Development
http://www.ibm.com/developerworks/data/library/techarticle/0206sqlref/0206sqlref.html

--
Helmut K. C. Tessarek
DB2 Performance and Development
IBM Toronto Lab