Performance Issues: FindFirst and Findset

fazlehasan

Hi,

We are using NAV 5.0 SP1 and SQL 2012.

I have a scenerio where I have to deal with the First Record in a record set differently than the rest of the records in the recordset;

I know using repeat..until inside FIRSTFIRST is not recommended.
So I was wondering between (A) and (B) which would be better performing:

(A)
IF FINDSET then begin
if FirstRecordFlagVar then begin
Do Something with the First record in the recordset;
end
else begin
repeat
Do Something with other records in the recordset;
until NEXT=0;
end;
end;

(B)

IF FINDFIRST then begin
Do Something with the First record in the recordset;
While (NEXT<>0) Do begin
Do Something with other records in the recordset;
end;
end;

(I am losing the indentation in the preview, sorry for that)
(It's second time I am posting it, last time my post was lost to oblivion, when I mistakenly did not put the Subject Line, may be webmaster can take care of it)

Thanks
Fazle

MBerger

i would go option B, but altered :

IF FINDSET then begin
  Do Something with the First record in the recordset;
  While (NEXT<>0) Do begin
    Do Something with other records in the recordset;
  end;
end;

fazlehasan

Thanks @MBerger.

But in C/Side Reference Guide they are saying:
You should only use this(FINDSET) function when you explicitly want to loop through a recordset. You should ONLY use this function in combination with REPEAT .. UNTIL

So WHILE Loop can be used inside FINDSET?

Thanks

Reinhard

Fazle,
Yeah, you can do that. Only the "NEXT" actually generates a server call.

Also use the [ code ] tags like MBerger has done to keep the formatting on your code.

- Reinhard

bbrown

I would likely go with something like this. Also the size of the record set and what I am doing would determine if I use FINDSET or FIND('-') and the parameters on FINDSET.

RecordNo := 0;
// set keys and filters
IF FINDSET THEN
  REPEAT
    RecordNo += 1;
    IF RecordNo = 1 THEN BEGIN
      // code for first record
    END  ELSE BEGIN
      // code for other records
    END;
  UNTIL NEXT = 0;

fazlehasan

Thanks @bbrown,@Reinherd,@Mberger for your inputs.
=D> =D> =D>