Beginning in SAS release 7, A NOTE is output when a variable is on an input data set and is also used for an I/O option. I/O options include data set options, SET/MERGE/UPDATE/MODIFY options, and INFILE/FILE options. The NOTE says:

 
    NOTE: The variable FOO exists on an input data set, 
    but was also specified in an I/O statement option.  
    The variable will not be included on any output data 
    set.

While true, the value of the variable may not be what you expect. For example:

    MERGE X(in=A) Y(in=B);
    BY byvar;

If the data set Y contains the variables A and B, the values for A and B come from an input data set when data is read from that data set and from the IN= option when data isn't read from that data set.

Beginning with SAS 9.1, a warning is issued:

WARNING: The variable FOO exists on an input data set and is also set by an I/O statement option. The variable will not be included on any output data set and unexpected results may occur.

While the note has been changed to a warning when the above situation is true, a NOTE will still be produced when the I/O option only reads the value of a variable. For example, the POINT= option on a SET statement reads that variable name and wouldn't try to read the same name from a SAS data set. The above NOTE is output.

Operating System and Release Information

Product Family	Product	System	SAS Release
			Reported	Fixed*
SAS System	Base SAS	z/OS	9.1 TS1M0
		Microsoft® Windows® for 64-Bit Itanium-based Systems	9.1 TS1M0
		Microsoft Windows Server 2003 Datacenter 64-bit Edition	9.1 TS1M0
		Microsoft Windows Server 2003 Enterprise 64-bit Edition	9.1 TS1M0
		Microsoft Windows 2000 Advanced Server	9.1 TS1M0
		Microsoft Windows 2000 Datacenter Server	9.1 TS1M0
		Microsoft Windows 2000 Server	9.1 TS1M0
		Microsoft Windows 2000 Professional	9.1 TS1M0
		Microsoft Windows NT Workstation	9.1 TS1M0
		Microsoft Windows Server 2003 Datacenter Edition	9.1 TS1M0
		Microsoft Windows Server 2003 Enterprise Edition	9.1 TS1M0
		Microsoft Windows Server 2003 Standard Edition	9.1 TS1M0
		Microsoft Windows XP Professional	9.1 TS1M0
		64-bit Enabled AIX	9.1 TS1M0
		64-bit Enabled HP-UX	9.1 TS1M0
		64-bit Enabled Solaris	9.1 TS1M0
		HP-UX IPF	9.1 TS1M0
		Linux	9.1 TS1M0
		OpenVMS Alpha	9.1 TS1M0
		Tru64 UNIX	9.1 TS1M0

* For software releases that are not yet generally available, the Fixed Release is the software release in which the problem is planned to be fixed.

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Type:	Usage Note
Priority:
Topic:	SAS Reference ==> DATA Step SAS Reference ==> Statements ==> File-handling ==> MERGE SAS Reference ==> Statements ==> File-handling ==> MERGE ==> with IN= SAS Reference ==> Statements ==> File-handling ==> SET SAS Reference ==> Statements ==> File-handling ==> UPDATE

Date Modified:	2008-09-02 15:30:26
Date Created:	2008-08-29 13:59:24