Maintaining OLAP Groups and OLAP Summary Data Stores

Overview

OLAP (online analytical processing) is a reporting technology that provides high-performance analysis and easy reporting of large amounts of data, that have been summarized. OLAP reporting functionality is possible because the detail data has been transformed--set up for an OLAP application to reflect the dimensions of the data. That is, the following has occurred:

The detail data has been summarized, which is a process that generates derived summary data by applying calculations to input data.
The derived summary data is stored in a summary data store, which is a physical storage file such as a relational table or an MDDB (multidimensional database).
The summary data store is available to an OLAP application.

SAS/Warehouse Administrator supports OLAP reporting by enabling you to create these data warehouse objects:

OLAP Group	is a grouping element that organizes related summary data, which is stored in OLAP Tables and OLAP MDDBs. OLAP Group properties specify the logical structure of the summarized data. You can add an OLAP Group to a Subject only.
OLAP Table	is a metadata record that specifies a file for storing derived summary data. This file can be a SAS table or view or a DBMS table or view. To load an OLAP Table, SAS/Warehouse Administrator generates code for the SUMMARY procedure, which summarizes data by computing descriptive statistics for columns across all rows or within groups of rows. Note that an OLAP Table can also be used by non-OLAP applications. You can add an OLAP Table to an OLAP Group only.
OLAP MDDB	is a metadata record that specifies a SAS MDDB (multidimensional database). A SAS MDDB is not a SAS table. It is a specialized storage format that stores derived summary data in a multidimensional form, which is a highly indexed and compressed format. To load an OLAP MDDB, SAS/Warehouse Administrator generates code for the MDDB procedure, which summarizes data similar to the SUMMARY procedure. You can add an OLAP MDDB to an OLAP Group only.

In general, to maintain OLAP Groups and OLAP summary data stores, you will do the following:

Analyze the detail data to understand its content and the relationships among the data.
Evaluate the most likely data access patterns to determine the storage strategy.
Define the properties of the OLAP Group.
Define the properties of the summary data store(s) for the OLAP Group; that is, define the OLAP Tables and OLAP MDDBs.
Define the Process Editor Job(s) that include the data preparation processes, which prepare the data to be summarized, and the Load Steps, which define the steps to summarize the data and load the OLAP summary data stores with derived data.
Execute the Jobs.
Verify that the summary data stores are loaded; that is, check logs, use the data utilities, and so on.

After you have defined and loaded OLAP objects, the OLAP metadata can be used by an OLAP application. Using SAS/Warehouse Administrator, for example, you can export the OLAP metadata to SAS/EIS software.

Note: The basic steps for creating OLAP objects are described in the online Help. To display the relevant online Help, in the SAS System Help contents, select Help on SAS Software Products, then Using SAS/Warehouse Administrator Software. Finally, select Defining Summary Data Stores. In addition, each SAS/Warehouse Administrator window has associated reference information for its fields and buttons by selecting the Help button. [cautionend]

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