Perfomance issues with Natural calling DB2 on VM/CMS

We are experiencing problems with Natural running on VM/CMS and calling a DB2 database. Especially when retrieving large data sets, Natural becomes much slower than e.g. COBOL (a reason for the client to migrate some Natural to COBOL :frowning: :x )

We tried:

  • Natural optimiser compiler (5 or 10 % gain, not a lot - little processing)

Should we consider:

  • Entire Access
  • rewriting the SQL
  • do more sorting in the DB (DB2)
  • using triggers in DB2 to do work before transferring to Natural
  • split work files
  • whatever :slight_smile:

How can we measure where the time is spent and how we can improve?
What is the best ratio of performance we should reach compared to COBOL (which will always be faster for some operations, I guess).
We want to make a case to get COBOL out of the customer.

Does this mean you are retrieving workfiles, importing that data into DB2 ?

otoh would suggest you are reading DB2, then write out to a workfile.

Can you please clarify what the task at hand is ?

When rewriting in COBOL, are SQL statements transferred 1:1, or rewritten as well ? In that case you can probably learn from it and tune your “NATURAL SQL”.

I shall try to get some code that show the way of working. I am speaking for a customer in Belgium.