|Oracle® OLAP DML Reference
10g Release 1 (10.1)
Part Number B10339-02
COUNT(boolean-expression [[STATUS] dimensions])
The Boolean expression whose
TRUE values are to be counted.
Can be specified when one or more of the dimensions of the result of the function are not dimensions of the Boolean expression. (See the description of the dimensions argument.) When you specify the STATUS keyword when this is not the case, Oracle OLAP produces an error.
In cases where one or more of the dimensions of the result of the function are not dimensions of the Boolean expression, the STATUS keyword might be required in order for Oracle OLAP to process the function successfully, or the STATUS keyword might provide a performance enhancement. See "The STATUS Keyword".
The dimensions of the result. By default, COUNT returns a single count of all
TRUE values. When you indicate one or more dimensions for the results, COUNT counts
TRUE values along the dimensions that are specified and returns an array of values. Each dimension must be either a dimension of boolean-expression or related to one of its dimensions. When it is a related dimension, you can specify the name of the relation instead of the dimension name. This enables you to choose which relation is used when there is more than one.
COUNT is affected by the NASKIP option. When NASKIP is set to
YES (the default), COUNT returns the number of
TRUE values of the Boolean expression, regardless of how many other values are
NA. When NASKIP is set to
NO, COUNT returns
NA when any value of the expression is
NA. When all the values of the expression are
NA, COUNT returns
NA for either setting of NASKIP.
When boolean-expression is dimensioned by a dimension of type DAY, WEEK, MONTH, QUARTER, or YEAR, you can specify any other DAY, WEEK, MONTH, QUARTER, or YEAR dimension as a related dimension. Oracle OLAP uses the implicit relation between the dimensions. To control the mapping of one DAY, WEEK, MONTH, QUARTER, or YEAR dimension to another (for example, from weeks to months), you can define an explicit relation between the two dimensions and specify the name of the relation as the dimension argument to the COUNT function.
For each time period in the related dimension, Oracle OLAP counts the
TRUE data values for all the source time periods that end in the target time period. This method is used regardless of which dimension has the more aggregate time periods.
When one or more of the dimensions of the result of the function are not dimensions of the Boolean expression, Oracle OLAP creates a temporary variable to use while processing the function. When you specify the STATUS keyword, Oracle OLAP uses the current status instead of the default status of the related dimensions for calculating the size of this temporary variable.
When the size of the temporary variable for the results of the function would exceed 2 gigabytes, you must specify the STATUS keyword in order for Oracle OLAP to execute the function successfully. When the dimensions of the Boolean expression are limited to a few values and are physically fragmented, you can specify the STATUS keyword to improve the performance of the function.
When you use the COUNT function with the STATUS keyword in an expression that requires going outside of the status for results (for example, with the LEAD or LAG functions or with a qualified data reference), the results outside of the status will be returned as
Example 9-28 Counting True Values by District
You can use COUNT to find the number of months in which each district sold more than 2,000 units of sportswear. To obtain a count for each district, specify
district as the dimension for the result.
LIMIT product TO 'SPORTSWEAR' REPORT HEADING 'Count' COUNT(units GT 2000, district)
The preceding statement statements produce the following output.
DISTRICT Count -------------- ---------- Boston 0 Atlanta 23 Chicago 11 Dallas 24 Denver 7 Seattle 0