lookups and performance

["Jon Paris" <Jon.Paris@xxxxxxxxxxxxxx>]

 >> I wonder whether there's any benefit to be derived from calling
 >> C-functions instead of doing the RPG ops, e.g. qsort rather
 >> than SORTA and bsearch rather than %lookup?

There are a number of advantages for qsort in particular.  Most of the
advantages of bsearch disappear with the advent of %Lookup.

Major advantages are:

 1) qsort can sort anything - into any sequence.  It can sort an array, or a
MODS, or any single chuck of memory.
 2) You determine the sort sequence.  Using qsort you can get "ACME" and
"Acme" and "acme" to be sequenced together, since you completely control the
sort sequence.
 3) qsort can sort dynamic memory - SORTA requires that the memory for the
whole array be allocated.
 4) SORTA sorts the whole array - even if only 20% of the entries are
filled.  qsort sorts as many elements as you tell it to.

Of these, only 1 and 2 really apply to bsearch - %lookup handles 3 and 4.

Jon Paris
Partner400
www.Partner400.com