RE: a need for speed

[qsrvbas@xxxxxxxxxxxx (Tom Liotta)]

AFAIK, Booth's method would "work", but Scott's _could_ easily be faster. The 
ordering would be the same for both and grouping would be defined the same. 
Scott positions-to and READs the first and last record in every group giving 
lowest and highest suffix (as long as ordering and grouping are correct) in the 
group. Booth's method would give the lowest suffix at L1-Detail time and the 
highest at L1-Total time.

However, Scott has a point when the average number of records in groups exceeds 
some number. If records are 1000 bytes in size and groups average say 50000 
records, then maybe it's not such a good idea to read individual records. But 
if groups average 5 records, then it hardly matters whether records are all 
read or not -- most will be physically read anyway and there'll be no READPs 
nor any other complicating code paths internally.

Tom Liotta

rpg400-l-request@xxxxxxxxxxxx wrote:

>   9. RE: a need for speed (Joe Pluta)
>
>Oh wait... (dusting off mental cobwebs)... can you order the records by
>area, prefix, suffix and terminal but tell RPG to level break on area,
>prefix and terminal??
>
>It's been a long time, but IIRC you can do that sort of thing.  If you
>can, then indeed Booth's concept would work and would probably be very,
>very fast since all the compares would occur under the RPG cycle covers.
>
>Joe
>
>> From: Joe Pluta
>> 
>> Won't work!  Either suffix is L3 and terminal is L4, or vice versa.
>On
>> the former, you break on every record.  On the latter, you miss the
>> multiple ranges.