The SAS Language Reference (p. 367) states:

"The subsetting IF statement selects observations that have been read into the program data vector. The WHERE statement selects observations before they are brought into the program data vector. The subsetting IF is less efficient than the WHERE statement because it must read each observation from the input data set into the program data vector."

Paul Gorrell gorrelp1@westat.com

____________________Reply Separator____________________ Subject: Re: The WHERE statement does not work for rawdata Author: "Lambert; Bob" <Bob_Lambert@AFCC.COM> Date: 04/21/1999 1:01 PM

I believe the WHERE statement processes conditions BEFORE the PDV is loaded and is therefore more efficient than the IF statement. I would appreciate further clarification or debunkfication on this.

Thanx,

Bob Lambert > -----Original Message----- > From: Adolf Quast [SMTP:adolf-a.quast@DB.COM] > Sent: Wednesday, April 21, 1999 7:25 AM > Subject: Re: The WHERE statement does not work for rawdata > > Hi, > > the WHERE statement is very efficient because it uses the information > stored in > the PDV (program data vector) of a SAS-dataset. The PDV is created when a > SAS-Dataset is built. The PDV contains information about field length and > type. > Your rawdata do not have a PDV, so they have to be read via INFILE and > INPUT. > > Greetings > Adolf Quast