Date:         Fri, 31 Jul 1998 10:01:24 -0700
Reply-To:     "Tang, Dennis" <dtang@AMGEN.COM>
Sender:       "SAS(r) Discussion" <SAS-L@UGA.CC.UGA.EDU>
From:         "Tang, Dennis" <dtang@AMGEN.COM>
Subject:      FW: Many-to-Many Merge
Content-Type: text/plain

Does it really?  I thought SAS will only give you a simple merge that
returns with number of rows of either the first data set or the second
data set, depending on which has more rows.
 
(Addition to last post) Unless you use proc sql which will give a
Cartesian match.
 
Correct me if I am wrong.
 
Dennis Tang
 
----------
From:  HERMANS1[SMTP:HERMANS1@WESTAT.COM]
Sent:  Friday, July 31, 1998 8:52 AM
To:  SAS-L@UGA.CC.UGA.EDU
Subject:  Re: Many-to-Many Merge
 
SAS does.  An unrestricted R<<->>R merge (or join) produces a
Cartesian product.  The dataset it produces contains a number of rows
or obs equal to the number of rows in the first dataset times the
number of rows in the second dataset.  A merge restricted to groups
produces a dataset with a number of rows equal to the sum of all
group1 rows times group2 rows.  In either case, these merges often
produce either great volumes of data or misleading results, or both.
Sig
______________________________ Reply Separator
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Subject: Many-to-Many Merge
Author:  Lau Anna <ylau1@UMBC.EDU> at Internet-E-Mail
Date:    7/31/98 12:10 AM
 
 
Hi, I need to merge two tables together and it's a many-to-many merge.
Does anyone know if SAS support this kind of merge? Thanks for any
information.
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                                                                ANNA