RE: Date arithmetic - performance dog?

["Mike Haston ** Data" <MHaston@xxxxxxx>]

That's worth a try.  I never even thought of that.  Here's an example of 
something the program does many times.  In looking at it now, I think I even 
TEST(D E) endDate further down in the process which makes no sense!  The 
routine is done thousands of times and the other routine gets into the 
millions.  Might make a difference.  Thank you.


 * test for valid date.                                                  
c                   test(d e)               XQ03                         
c                   if        not %error                                 
                                                                         
 * if XQ03's week ending date is beyond today, set the week start/end to 
 * the previous week's                                                   
c                   if        #getWkEndDate( %date(XQ03) ) > jobDate     
c                   eval      beginDate = #getPrvWkStart( jobDate )      
c                   eval      endDate = #getPrvWkEnd( jobDate )          
c                   move      endDate       endDate#                     
                                                                         
 * else set valid week start and end dates                               
c                   else                                                 
c                   eval      beginDate = #getWkStrDate( %date(XQ03) )   
c                   eval      endDate = #getWkEndDate( %date(XQ03) )     
c                   endif                                                
                                                                         
 * else invalid date, set week start/end dates to previous week          
c                   else                                                 
c                   eval      beginDate = #getPrvWkStart( jobDate )      
c                   eval      endDate = #getPrvWkEnd( jobDate )          
c                   endif                                                
                                                                         



-----Original Message-----
From: Hans Boldt [mailto:boldt@xxxxxxxxxx]
Sent: Thursday, May 15, 2003 9:12 AM
To: rpg400-l@xxxxxxxxxxxx
Subject: Re: Date arithmetic - performance dog?


Mlpolutta@xxxxxxx wrote:
> I wanted to see if you folks have found that ADDDUR and SUBDUR (etc.), and 
> MOVEing to/from date fields are REALLY poor performers - it sure seems that 
> way to me.  Is there a way to make such things perform well?

The performance of the date/time/timestamp operations is indeed a 
touch on the slow side. The reason is that each operation does a 
validity check on the values.

The only suggestion I have is that if you're converting from 
character or numeric to a D/T/Z value, don't check first using a 
TEST operation. Just convert directly using the appropriate built-in 
function (%DATE, %TIME, or %TIMESTAMP) wrapped in a MONITOR group. 
That will at least save one validity check.

For example:

MONITOR;
    DATE=%DATE(DSTR:*YMD);
ON-ERROR 112;
    DSPLY 'Egads! We have a bad date value!';
ENDMON;

Cheers! Hans