Specifies whether SAS creates compressed data sets whose observations
can be randomly accessed or sequentially accessed.
Valid in: |
DATA step and PROC steps
|
Category: |
Observation Control
|
Restriction: |
POINTOBS= is effective only when creating
a compressed data set. Otherwise it is ignored.
|
-
YES
-
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:
Tip: |
Specifying POINTOBS=YES
does not affect the efficiency of retrieving information from a data set,
but 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% when creating a compressed
data set and when updating or adding observations to it by specifying POINTOBS=NO. |
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.
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Data Set Options:
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System
Options:
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Copyright © 2011 by SAS Institute Inc., Cary, NC, USA. All rights reserved.