DB2 OLAP Server 1.0

Touted by IBM as offering the power of Arbor Essbase OLAP Server 5with the robustness of DB2, IBM's DB2 OLAP Server 1.0 integrates Essbase'sonline analytical processing (OLAP) server and APIs with IBM's DB2 family ofrelational databases. DB2 OLAP Server uses a star schema structure to store datain DB2. Typically, the Essbase engine calculates the data in the star schema.You can use Essbase clients or traditional SQL tools to access the data. DB2OLAP Server manages the relational storage within the star schema and therelationship between Essbase and DB2.

Nigel Pendse, co-author of The OLAP Report (http://www.olapreport.com), jokingly refers to the DB2 OLAP Server as a "dieselEssbase" because it merges the two dissimilar technologies at high cost. "IBMdid a fine job of implementing the DB2 layer," observes Pendse. "Theproblem is that IBM is converting a highly optimized, patented compressed cubestructure into vanilla relational rows. These rows take about twice as muchspace to store and have less appropriate, bulkier indexing. Both factors combineto make access to the data much slower."

Nevertheless, the DB2 OLAP Server is an attractive option for DB2 shopsthat want an easy-to-implement OLAP solution. You install it with one CD-ROM. Aswith Essbase, you create a database outline, define dimensions and members, andspecify dimensions as dense or sparse. However, in DB2 OLAP Server, you have tospecify an Anchor tag, which is akin to Essbase's Accounts tag.

DB2 OLAP Server operates on Windows NT, OS/2, AIX, and Solaris. Itmaintains and analyzes data stored in IBM's DB2 family, including DB2 UniversalDatabase (UDB), DB2 for OS/390, and DB2 for OS/400. Aside from the relationalstorage management function, DB2 OLAP Server offers the same functionality asEssbase. According to Arbor, 98 percent of the OLAP code in DB2 OLAP Server isthe same as the OLAP code in Essbase. Queries perform similarly, although DB2OLAP Server's load and calculation processes take longer because of the tightDB2-to-Essbase mapping.