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computer · Posted: Mon Dec 20, 2010 2:03 am Post subject: Few Queries on Cursors - DB2

Hi,

The cursor functionality in a cobol program goes this way:
-- Declare Cursor : Definition of the query
-- Open Cursor: Cursor gets executed and the pointer is set to first record in the cursor result
-- Fetch Cursor: Data retrieve happens and populated to host variables
-- Close cursor: closing the cursor

I have following few questions:
1. What happens in this following case....
Open Cursor1
Fecth Cursor1

Open Cursor1
Fetch Cursor1
Close Cursor1

2. If have 50 records to display on the screen, 10 max at a time...
So, which is better option to go for
a) Use of TSQ and store all the records and then send 10 recs at a time to screen. or,
b) Use of inbuilt DB2 scrollable functionality.

(Do not have strobe access to analyze performance for the above)

Thanks in Advance,
Computer

dbzTHEdinosauer · Posted: Mon Dec 20, 2010 2:26 am Post subject:

storing data in a tsq is handy, especially if you KNOW that all will be accessed.

There are size restrainsts (the more cics memory you use for your transaction, the less there is available for others.

There is also the problem (required logic) to delete the queue items when the transaction is complete.

you are only displaying 10 items per screen - invocation of the program.
the cursor will be closed after your program issues the cics return.

what are the requirements of your transaction? to only provide scrollablility to data,
or
can a user jump from page 1 to page 3?

answers to above will help in determining your logic.
_________________
Dick Brenholtz
American living in Varel, Germany

computer · Posted: Mon Dec 20, 2010 7:11 am Post subject:

dbzTHEdinosauer,

My requirement is only to display the data in forward/backward sequence.

And one more thing, we have a convention of deleting all the TSQs created once the master transaction program terminates.

Also, any thoughts on Query-1.

Thanks In Advance
Computer

dbzTHEdinosauer · Posted: Mon Dec 20, 2010 9:36 am Post subject:

i would save the last keys in dfhcommarea and not use the tsq.

i would always close the cursor within the program.
_________________
Dick Brenholtz
American living in Varel, Germany

kolusu · Posted: Mon Dec 20, 2010 12:42 pm Post subject:

computer,

You need to understand the concept of Pseudo conversation. Read about it here

http://publib.boulder.ibm.com/infocenter/cicsts/v2r2/index.jsp?topic=/com.ibm.cics.ts22.doc/dfhp3/dfhp35g.htm

Kolusu