causes SAS software
to produce a compressed data set that might be randomly accessed by
observation number. This is the default.
Examples of accessing
data directly by observation number are:
the POINT= option of the MODIFY
and SET statements in the DATA step
going directly to a specific observation
number with PROC FSEDIT.
Tip
Specifying POINTOBS=YES does
not affect the efficiency of retrieving information from a data set.
It does increase CPU usage by approximately 10% when creating a compressed
data set and when updating or adding information to it.
NO
suppresses the ability
to randomly access observations in a compressed data set by observation
number.
Tip
Specifying POINTOBS=NO is
desirable for applications where the ability to point directly to
an observation by number within a compressed data set is not important.
If you do not need to access data by observation number, then you
can improve performance by approximately 10% by specifying POINTOBS=NO:
when creating a compressed data
set
when updating or adding observations
to it
Details
Note that REUSE=YES
takes precedence over POINTOBS=YES. For example:
data test(compress=yes pointobs=yes reuse=yes);
results in a data set that has POINTOBS=NO. Because POINTOBS=YES
is the default when you use compression, REUSE=YES causes POINTOBS=
to change to NO.