Re: Performance hit with trigger program

[Dan <dan27649@xxxxxxxxx>]

Thanks Alan.

So, I've made both the trigger program and the data queue listener program
MAIN programs with named AGs.  In my performance tests, the trigger program
is about 50% faster.

For testing purposes, I opened another interactive session and called the
data queue listener program.  It waits until there is a record insert,
update, or delete in the triggered file.  Then the program ends.  Other
than that, it works as expected (adds records to a log file).  I noticed in
your example that there is a Return op code, and I have one in mine.
Should I be coding some kind of loop?  How does the loop terminate, say,
when I need to shut down the subsystem where the listener programs run?

     h ActGrp('TRG001RRDQ')
DftActGrp(*No)
     h
Main(RcvDtaQ001)
     p RcvDtaQ001
b
     fTRG001H   o    e
disk
     d TriggerRecord e ds                  ExtName( OWNER
)
     d
Qualified
     d  TrgType                       1    Overlay( TriggerRecord : *Next
)
     d  TrgTmStamp                     z   Overlay( TriggerRecord : *Next
)


     d OutputRecord  e ds                  ExtName( TRG001H   : *Output
)


     d Sequence#       s             15  0
Static
     d DtaQLength      s              5p 0
Static


     d RcvDtaQ         pr                  ExtPgm( 'QRCVDTAQ'
)
     d  dtaqname                     10A
const
     d  dtaqlib                      10A
const
     d  dtaqlen                       5P 0
const
     d  data                      32766A   const
options(*varsize)
     d  dtaqwait                      5P 0
const

          RcvDtaQ( 'TRG001DTAQ' : '*LIBL' : DtaQLength : TriggerRecord : -1
);

          Eval-Corr OutputRecord = TriggerRecord;
          Sequence# =+ 1;
          TrgSequenc = Sequence#;
          Write TRG001Hr OutputRecord;

          Return;
     p RcvDtaQ001      e

On Thu, Apr 7, 2016 at 6:22 PM, Alan Campin <alan0307d@xxxxxxxxx> wrote:

> The other thing to think about assuming your at V6R1 or higher. Make any
> callable program a Main program. It eliminates the cycle, runs aobut 20%
> faster and cuts size of program.
>
> Going to use free format here. Easy enough to translate back to fixed.
>
> Use a named activation group for best performance and assuming all this
> program is going to do is write to data queue. Always recommend mediator.
> In that case, this would be a very simple Service Program.
>
> **FREE
>
> ctl-opt Option(*Srcstmt:*Nodebugio:*Nounref);
> ctl-opt Main(ProcessTransaction);
>
> dcl-ds TD_DbTriggerBuffer Qualified Template;
>   PhysicalFileName Char(10);
>   PhysicalFileLibrary Char(10);
>   PhysicalFileMember Char(10);
>   TriggerEvent Char(1);
>   TriggerTime Char(1);
>   CommitLockLevel Char(1);
>   Reserve1 Char(3);
>   CCSIDOfData Int(10);
>   RelativeRecordNumber Int(10);
>   Reserve2 Char(4);
>   BeforeOffset Int(10);
>   BeforeLength Int(10);
>   BeforeNullByteOffset Int(10);
>   BeforeNullByteLength Int(10);
>   AfterOffset Int(10);
>   AfterLength Int(10);
>   AfterNullByteOffset Int(10);
>   AfterNullByteLength Int(10);
>   Reserved3 Char(16);
> end-ds;
>
> dcl-pr ProcessTransaction ExtPgm('YOURNAME');
>   PR_InTriggerBuffer LikeDs(TD_DbTriggerBuffer);
>   PR_InBufferLength Int(10) Const;
> end-pr;
>
> dcl-proc ProcessTransaction;
>   dcl-pi *N;
>     InTriggerBuffer LikeDs(TD_DbTriggerBuffer);
>     InBufferLength Int(10) Const;
>   end-pi;
>
>   // declare all variables as local to procedure. As little static as
> possible.
>
>   // Your write data queue logic.
>
>   Return;
>
> end-proc;