Multidimensional queries

QMF for Workstation and QMF for WebSphere® support multidimensional analysis through the use of OLAP queries.

OLAP queries are multidimensional queries that can present your cube data in a wide variety of views. You can drill up, down, or across through a user-defined set of dimensions and levels by using the built-in OLAP explorer. You can then use the OLAP query diagram to create a new OLAP query, or open an existing query and modify it to obtain different views of the cube data.

A multipane OLAP editor provides side-by-side views of the cube and the OLAP query that you are creating, as shown in the following figure. Dimensional filtering allows you to include only the data that you want to analyze, increasing the efficiency of retrieving data from larger cubes. Hierarchical dimensional filtering allows you to filter dimension levels in relation to the cube contents. For example, a view of the second quarter can be filtered across all years or merely across a designated list of years. At any given time, you can view the underlying SQL or MDX statements that have been automatically generated in response to a query that you have created graphically.
Figure 1. The multipane OLAP editor, which provides two different views of an OLAP query
This figure shows the two different views provided for an OLAP query in the QMF for Workstation OLAP editor. The left side of the graphic is labeled "Cube Structure" and the right side is labeled "Query Structure". Beneath "Cube Structure" is the text "Dimensions and measures in this cube". Beneath that text is a hierarchy. At the top level is "General Sales," followed by "Dimensions" and "Measures" at the next level. Beneath "Dimensions" are "Product," "Market," and "Time". Beneath "Measures" are "SALES (SALESFACT)," "COGS (SALESFACT)," "ADVERTISING (SALESFACT)," "Total Expense," and "Profit." On the right side, below the text "Query Structure," is the text "Dimensions and measures selected for query," with a hierarchy just below that. The top level of the hierarchy is "Layout". The next level contains "Top Dimensions," "Side Dimensions," and "Measures". Beneath "Top Dimensions" is "Market," and below that is "REGION_NAME". Beneath "Side Dimensions" is "Time," and below that is "FISCAL_YEAR". Beneath "Measures" are "SALES (SALESFACT)" and "COGS (SALESFACT)".

As with relational queries, QMF for Workstation and WebSphere offer multiple methods of constructing multidimensional queries. You can browse available cube models and construct queries by graphically dragging and dropping dimensions and measures of interest into your queries and immediately see the results of your selections. Although no coding knowledge is required to browse and construct OLAP queries, experienced users can open the Multidimensional Expressions (MDX) editor and directly enter or edit the query's underlying MDX statements. You can also switch between the MDX and graphical editors, building the query by using a blend of both methods.

You can format OLAP query results directly in the query results editor, which provides many options, including the ability to:
  • View summary information for a measure or dimension
  • View only totals for a measure or summarized dimension
  • View detailed data for a summarized dimension
  • Resize columns
  • Change the font or format for a measure or dimension

OLAP cube data can be displayed in both QMF for Workstation and QMF for WebSphere, and can be directly incorporated into visual reports and dashboards by using the OLAP-aware charts, graphs, and dimension slicers in QMF for Workstation.