DATASETS Procedure
INDEX CREATE Statement
Creates simple or composite indexes for the SAS
data set specified in the MODIFY statement.
Syntax
Required Argument
- index-specification(s)
-
can be one or both
of the following forms:
- variable
-
creates a simple index
on the specified variable.
- index=(variables)
-
creates a composite
index. The name that you specify for index is
the name of the composite index. It must be a valid SAS name and
cannot be the same as any variable name or any other composite index
name. You must specify at least two variables.
Note:The index name must follow the same rules as a SAS variable
name, including avoiding the use of reserved names for automatic variables,
such as _N_, and special variable list names, such as _ALL_. For more
information, refer to “Rules for Words and Names in the SAS
Language” in SAS Language Reference: Concepts.
Optional Arguments
- NOMISS
-
excludes from the index
all observations with missing values for all index variables.
When you create an
index with the NOMISS option, SAS uses the index only for WHERE processing
and only when missing values fail to satisfy the WHERE expression.
For example, if you use the following WHERE statement, SAS does not
use the index, because missing values satisfy the WHERE expression:
where dept ne '01';
Refer
to
SAS Language Reference: Concepts.
BY-group processing
ignores indexes that are created with the NOMISS option.
- UNIQUE
-
specifies that the
combination of values of the index variables must be unique. If you
specify UNIQUE and multiple observations have the same values for
the index variables, the index is not created.
- UPDATECENTILES=ALWAYS | NEVER | integer
-
specifies when centiles
are to be updated. It is not practical to update centiles after every
data set update. Therefore, you can specify the percentage of the
data values that can be changed before centiles for the indexed variables
are updated. The following is a list of valid values:
- ALWAYS | 0
-
updates centiles when
the data set is closed if any changes have been made to the data set
index. You can specify ALWAYS or 0 and produce the same results.
- NEVER | 101
-
does not update centiles.
You can specify NEVER or 101 and produce the same results.
- integer
-
specifies the percentage
of values for the indexed variable that can be updated before centiles
are refreshed.
Alias:UPDCEN
Default:5 (percent)
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