SAS System Options

SORTDUP= System Option

Specifies whether the SORT procedure removes duplicate variables based on all variables in a data set or the variables that remain after the DROP or KEEP data set options have been applied.

Valid in:	configuration file, SAS invocation, OPTIONS statement, SAS System Options window
Category:	Sort: Procedure options
PROC OPTIONS GROUP=	SORT

Syntax
Syntax Description
Details
See Also

Syntax

SORTDUP=PHYSICAL | LOGICAL

Syntax Description

PHYSICAL: removes duplicates based on all the variables that are present in the data set. This is the default.
LOGICAL: removes duplicates based on only the variables remaining after the DROP= and KEEP= data set options are processed.

Details

The SORTDUP= option specifies what variables to sort to remove duplicate observations when the SORT procedure NODUPRECS option is specified.

When SORTDUP= is set to LOGICAL and NODUPRECS is specified in the SORT procedure, duplicate observations are removed based on the variables that remain after a DROP or KEEP operation on the input data set. Setting SORTDUP=LOGICAL increases the number of duplicate observations that are removed because it eliminates variables before observations are compared. Setting SORTDUP=LOGICAL might improve performance.

When SORTDUP= is set to PHYSICAL and NODUPRECS is specified in the SORT procedure, duplicate observations are removed based on all of the variables in the input data set.