| Oracle® OLAP Reference 10g Release 2 (10.2) Part Number B14350-01 |
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View PDF |
| Oracle® OLAP Reference 10g Release 2 (10.2) Part Number B14350-01 |
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View PDF |
OLAP_EXPRESSION acts as a numeric single-row function within the context of a SELECT FROM OLAP_TABLE statement. You can specify OLAP_EXPRESSION in the same way you specify other Oracle single-row functions, notably in the select list, WHERE , and ORDER BY clauses.
Single-row functions return a single result row for every row of a queried table or view. Oracle supports a number of predefined single-row functions, for example COS, LOG, and ROUND which return numeric data, and UPPER and LOWER which return character data. For more information on single-row functions, refer to the Oracle Database SQL Reference.
The OLAP single-row functions, OLAP_EXPRESSION and its variants for text, date, and boolean data, return the result of an OLAP DML expression that you specify. The OLAP DML supports a rich syntax for specifying computations ranging from simple arithmetic expressions to statistical, financial, and time-series operations. You can use OLAP_EXPRESSION to dynamically perform any valid numeric expression within an analytic workspace and retrieve its results. For more information on OLAP DML expressions, refer to the Oracle OLAP DML Reference.
OLAP_TABLE uses a limit map to present the multidimensional data from an analytic workspace in tabular form. The limit map specifies the columns of the logical table. When an OLAP_EXPRESSION function is specified in the select list of the query, OLAP_TABLE generates additional columns for the results of the function.
To use OLAP_EXPRESSION, you must specify a ROW2CELL clause in the limit map used by OLAP_TABLE. ROW2CELL identifies a RAW column that OLAP_TABLE populates with information used by the OLAP single-row functions.
