Program is taking too much time

kumar_jalluri · New User Joined: 02 Jun 2005 Posts: 24 Location: PUNE

Hi

I have one cobol program.

This program is using one VSAM file having one lakh records.

When it was stand alone it would finsih with in one minute.

Recently one sub program was included in this program which also usies the file information. Now when I run the program it is running for very long time.

Can anyone tell me what might be the reason for this and also one good solution.

Thanks in advance
Kumar

MFRASHEED · Active User Joined: 14 Jun 2005 Posts: 186 Location: USA

- Execute STROBE on program and see where exactly time is being spent.
- Do VSAM file have buffers on it, if not add buffers.

Without looking at code difficult to make suggestions. Can you put atleast PSEUDO CODE of what program is doing.

kumar_jalluri · New User Joined: 02 Jun 2005 Posts: 24 Location: PUNE

Even if I add a small program like doing small arithmatic operation it is so much of time.

what is buffers?

How can I increase these buffers.

Could u plz explain in more detail.

Thanks

MFRASHEED · Active User Joined: 14 Jun 2005 Posts: 186 Location: USA

Adding buffers to VSAM works like CACHE, reduces I/O and increases performance. What kind of buffers depends on VSAM processing, if VSAM is only Read only, (Dynamic or Sequential), READ and WRITE/RE-WRITE etc.

Read more about VSAM buffers and VSAM tunning in

www.redbooks.ibm.com/redbooks/pdfs/sg246105.pdf

Chapters:
2.6 Parameters affecting performance
2.6.13 Buffering options
2.6.14 Buffering techniques

Also best way is to execute STROBE or any other performance management tools your shop has.