Date:         Wed, 13 Jan 1999 08:35:22 +0200
Reply-To:     hwright@oldmutual.com
Sender:       "SAS(r) Discussion" <SAS-L@UGA.CC.UGA.EDU>
From:         Howard Wright <hwright@OLDMUTUAL.COM>
Subject:      Re: Combining large datasets
Comments: To: Bas Pruijn <bas.pruijn@CMG.NL>
Content-Type: text/plain; charset=us-ascii

Hi,
Try following (untested) code might help - it requires that dataset A and
B be sorted.
 
proc sort data=B;
run;
data A;
  set A B;
  by var1 var2 var3;
run;
The output dataset should be in var1 var2 var3 sort order.
 
This should be faster than what you've got at the moment.
 
HTH
 
Howard Wright
Cape Town
South Arica
 
 
 
Bas Pruijn wrote:
>
> I have a question:
>
> I have to combine 2 huge datasets. The biggest one is about 10M obs and the
> smallest (dataset B) about 1M obs. The biggest (lets say A) is sorted.
>
> The method I use right now is:
> * proc append base=a new=b;run;
> * proc sort data=a; by var1 var2 var3; run;
>
> This means sorting a 11M obs dataset, wich takes a *very* long time on
> HP-ux.
>
> I assume there is a smarter way of doing this.
>
> Greetings, Bas
>
> PS: Does it make a difference if A is not sorted, but indexed?