SAS Data Set Options

FIRSTOBS= Data Set Option

Specifies the first observation that SAS processes in a SAS data set.

Valid in:	DATA step and PROC steps
Category:	Observation Control
Restriction:	Valid for input (read) processing only.
Restriction:	Cannot use with PROC SQL views.

Syntax
Syntax Description
Details
Comparisons
Examples
See Also

Syntax

FIRSTOBS= n| nK | nM | nG | hexX | MIN | MAX

Syntax Description

n | nK | nM | nG: specifies the number of the first observation to process in multiples of 1 (bytes); 1,024 (kilobytes); 1,048,576 (megabytes); or 1,073,741,824 (gigabytes). For example, a value of 8 specifies the 8th observation, and a value of 3k specifies 3,072.
hexX: specifies the number of the first observation to process as a hexadecimal value. You must specify the value beginning with a number (0-9), followed by an X. For example, the value 2dx sets the 45th observation as the first observation to process.
MIN: sets the number of the first observation to process to 1. This is the default.
MAX: sets the number of the first observation to process to the maximum number of observations in the data set, up to the largest eight-byte, signed integer, which is 2⁶³-1, or approximately 9.2 quintillion observations.

Details

The FIRSTOBS= data set option affects a single, existing SAS data set. Use the FIRSTOBS= system option to affect all steps for the duration of your current SAS session.

FIRSTOBS= is valid for input (read) processing only. Specifying FIRSTOBS= is not valid for output or update processing.

You can apply FIRSTOBS= processing to WHERE processing. For more information, see Processing a Segment of Data That Is Conditionally Selected in SAS Language Reference: Concepts.

Comparisons

The FIRSTOBS= data set option overrides the FIRSTOBS= system option for the individual data set.
While the FIRSTOBS= data set option specifies a starting point for processing, the OBS= data set option specifies an ending point. The two options are often used together to define a range of observations to be processed.
When external files are read, the FIRSTOBS= option in the INFILE statement specifies which record to read first.

Examples

This PROC step prints the data set STUDY beginning with observation 20:

proc print data=study(firstobs=20);
run;

This SET statement uses both FIRSTOBS= and OBS= to read-only observations 5 through 10 from the data set STUDY. Data set NEW contains six observations.

data new;
  set study(firstobs=5 obs=10);
run;