55393 - The IMSTAT procedure updates all records if there are uninitialized variables in the CODE= program

Problem Note 55393: The IMSTAT procedure updates all records if there are uninitialized variables in the CODE= program

If you specify the CODE= option in an UPDATE statement and there are uninitialized variables in the SAS^® program, PROC IMSTAT updates every record in the target table. To avoid unintended updates, you should initialize all variables introduced in the user supplied SAS program. To initialize a variable, use a FORMAT statement, a LENGTH statement, or an assignment statement. (This does not apply to variables already in the active table being updated.)

Failure to initialize a variable can result in all records being updated. There are no notes in the SAS Log to indicate this has happened.

Here is an example. Suppose we load the SAS data set Sashelp.cars to LASR and run the following,

proc imstat; table lasr.cars; UPDATE / code=pgm1; quit;

where pgm1 is a fileref to a text file. Suppose the text file includes the following line of code:

if manufacturer="Mazda" then origin="Japan";

Since MANUFACTURER does not exist in Sashelp.cars, the value of ORIGIN is updated to "Japan" in every record of Lasr.cars.

To avoid this problem, initialize the variable MANUFACTURER in the SAS program using any of the following methods:

format manufacturer $10; if manufacturer="Mazda" then origin="Japan";

length manufacturer $10; if manufacturer="Mazda" then origin="Japan";

manufacturer = "Ford"; if manufacturer="Mazda" then origin="Japan";

For related notes about using the CODE= option in the UPDATE statement in PROC IMSTAT, see Problem Note 55419 and Problem Note 55420.

Operating System and Release Information

Product Family	Product	System	SAS Release
Product Family	Product	System	Reported	Fixed*
SAS System	SAS LASR Analytic Server	Microsoft® Windows® for x64	9.4 TS1M2	9.4 TS1M3
		64-bit Enabled AIX	9.4 TS1M2	9.4 TS1M3
		64-bit Enabled Solaris	9.4 TS1M2	9.4 TS1M3
		Linux for x64	9.4 TS1M2	9.4 TS1M3
		Solaris for x64	9.4 TS1M2	9.4 TS1M3

* 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.

If a variable is specified in a CODE= program and that variable does not exist in the data set, the UPDATE statement in PROC IMSTAT updates all records in the data set. This is most likely an unintended consequence, and there are no log messages to indicate this has happened

Type:	Problem Note
Priority:	high
Topic:	Analytics ==> analytics SAS Reference ==> Procedures ==> IMSTAT

Date Modified:	2016-06-15 12:16:08
Date Created:	2015-03-17 15:30:14

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Problem Note 55393: The IMSTAT procedure updates all records if there are uninitialized variables in the CODE= program

Operating System and Release Information