RE: Is a Read by Partial Key on a Keyed Data Queue allowed ?

Not really as they key length specified has to match what the data queue was created with.

But, since a keyed read allows GT, LT, NE, EQ, GE, and LE, operations, you might be able to accomplish what you're doing.

Just use the MAC-ID segment and zero out the timestamp segment. Do your read (GE) and the timestamp piece will be returned to you. Then, you can read (EQ) with the full key to do the remove.


Roger Harman
COMMON Certified Application Developer - ILE RPG on IBM i on Power



-----Original Message-----
From: RPG400-L [mailto:rpg400-l-bounces@xxxxxxxxxxxx] On Behalf Of Voris, John
Sent: Thursday, February 25, 2016 3:37 PM
To: rpg400-l@xxxxxxxxxxxx
Subject: Is a Read by Partial Key on a Keyed Data Queue allowed ?

Is reading from a Keyed Data Queue with a Partial Key allowed ?

If a Keyed Data-Queue has 2 keys, can we read from it with 1 key ?
(In Keyed Data Queues, keys are contiguous, like the old F-spec area for key-field-length. )


Scenario: We are using a keyed data queue holding pending activity
where MAC-ID of our new timeclocks is the key.
After the pending activity is done and we re-read the data queue
- this time with REMOVE(*YES) - it turns out, we are removing a different entry
than the one we first read and processed. Another process could have inserted
this other entry we removed or it could be that entries are not always guaranteed
to always be presented in the same order, just like SQL which does not
guarantee order-sequence unless you specified it explicitly.

A solutino is have MAC-ID and Timestamp as keys to our data queue,
on the first read, read by MAC-ID.
on the final read with REMOVE(*YES), read by MAC-ID and Timestamp.

- John Voris