Microsoft Corporation
Last updated July 20, 1998
Q. What is OLE DB for OLAP, and how is it related to Tensor?
A. Tensor was an internal code name for what is now Microsoft® OLE DB for OLAP. It is a set of COM interfaces designed to extend OLE DB for efficient access to multidimensional data. These extensions are built upon, and incorporate, existing OLE DB objects, thus leveraging the power of OLE DB and COM for business intelligence development. They are designed to link multidimensional data providers and consumers of such data, regardless of the data store environment. OLE DB for OLAP is part of OLE DB version 2.0.
Q. What corresponding ADO extensions can I use to access OLAP data?
A. ADO has been extended with new objects, collections, and methods that are designed to take advantage of OLE DB for OLAP. These extensions are collectively known as ADO MD. ADO and ADO MD are part of the overall Microsoft data access strategy and provide a simple, high-level object model for accessing tabular and OLAP data.
Q. What is OLE DB?
A. OLE DB is a set of COM interfaces that provide applications with uniform access to data stored in diverse information sources, regardless of location or type. OLE DB consumers use these interfaces to access data. OLE DB providers expose their data by implementing these interfaces. For more information, visit the Microsoft OLE DB Web site at http://www.microsoft.com/data/oledb/.
Q. What is OLAP?
A. OLAP stands for Online Analytical Processing. It is a category of software that enables users to perform sophisticated data analysis through fast, consistent, interactive access to a variety of possible views of the underlying information. OLAP typically handles huge volumes of data that is interrelated in complex ways.
Q. How is OLAP related to multidimensional databases?
A. Multidimensional databases provide efficient storage and retrieval of intimate information relationships, which are stored and viewed in various perspectives called dimensions. Each dimension is composed of a number of consolidation levels (aggregations), which allow further navigation by "drilling" up and down through the data. Multidimensional databases make up a significant percentage of data stores used for OLAP. Other implementations include multidimensional views on top of relational database systems. OLE DB for OLAP is designed to work with all implementation flavors of OLAP stores.
Q. Why should I use OLE DB for OLAP?
A. OLE DB for OLAP allows you to access OLAP data through a set of industry-standard interfaces. ISVs and corporate application developers can depend on a single interface for consuming OLAP data, regardless of the vendor or source. Providers of OLAP data can implement a single set of interfaces that allow all OLAP clients to access their data. Consumers can use the COM query interface and data source properties to dynamically adapt to provider capabilities. We expect OLE DB for OLAP to spawn a new market for interoperable OLAP tools.
Q. Will Microsoft applications such as Microsoft Excel consume OLE DB for OLAP?
A. Yes! The next major version of Microsoft Excel will consume these interfaces. Hence, Microsoft Excel will work out of the box with any provider that exposes OLE DB for OLAP. Future versions of Microsoft desktop and enterprise data analysis products also will use these interfaces to access OLAP data, providing greater product integration for Microsoft customers.
Q. Is this an open specification? How can I send my feedback?
A. Yes, OLE DB for OLAP is an open specification. It has been designed with extensive vendor participation. You can download the extensions for free, and you can implement them with the accompanying header files.
You can send feedback to oledbinf@microsoft.com, or you can post your comments on the public newsgroup microsoft.public.oledb.olap. The Microsoft OLE DB Support Group monitors this newsgroup, taking feedback information to the specification authors. Because of the broad distribution of this specification, we cannot guarantee individual responses to each feedback item. It is our intent that the newsgroup be a lively forum for sharing and discussing these issues.
Q. What should I know to use OLE DB for OLAP?
A. A working knowledge of COM and OLE DB is required. Because Microsoft based these extensions on the industry standard for OLE DB interfaces, consumers and providers can leverage their existing data access investments. OLE DB for OLAP employs full-fledged, highly functional expression syntax (multidimensional expressions, or MDX) for expressing queries. This syntax will be divided into concentric conformance levels, and the provider need only conform to the core level to be compliant. The core level will be designed to satisfy the needs of most OLAP tools.
Q. Will Microsoft provide an SDK?
A. Yes, it is a component of the Microsoft Data Access SDK. The OLE DB for OLAP Toolkit includes the OLE DB for OLAP specification, a sample provider that exposes these interfaces, header files, sample applications, and so on. The sample provider is full-featured, enabling consumers to troubleshoot their code. It also serves as a reference for provider implementations.
Q. Is OLE DB for OLAP a least-common-denominator approach?
A. No! OLE DB for OLAP defines properties whose values enable the applications to dynamically adapt to the provider's capabilities. Because OLE DB for OLAP is based on COM, consumers can query whether an interface is available before using it, giving it a further degree of scaling to provider implementation. Because the interfaces are extensible, providers can expose value-added features. Consumers write feature-specific code instead of vendor-specific code.
Q. Is OLE DB for OLAP read-only?
A. No! OLE DB for OLAP has interfaces to update the data in a cube. This version doesn't define any new interfaces for updating multidimensional schema (such as dimensions or members). However, the existing rowset update model in OLE DB can be used for updating schema information. The next release version will have specific mechanisms in place for updating schema and for DDL features.
Q. Can I use OLE DB for OLAP with Microsoft Visual Basic®?
A. Yes. As previously mentioned, Microsoft has extended its ADO interfaces to use OLE DB for OLAP, thereby making multidimensional data access widely available to Visual Basic components.
Q. Where can I find out more about OLE DB for OLAP? How can I download the specification?
A. Visit the Data Access Web site at http://www.microsoft.com/data/. The site has links to download the specification and also contains information about vendors who are implementing OLE DB for OLAP providers and consumers.
Q. In addition to Microsoft, what companies have announced support for OLE DB for OLAP?
A. Early support has been announced by a number of vendors, including: Acuity Group, Andyne Computing Limited, Application Consulting Group, Inc. (ACG), Applix TM1 Software, Arbor Software, arcplan, Inc., AVOCA Systems Limited, BAAN, Brio Technology, Business Objects, Cognos, Comshare, Gentia Software, Hyperion Software, Information Advantage Inc., International Software Group, InterNetivity, Intersolv, Inc., IQ Software, Knosys, MIS AG, NCR,Panorama Software Systems Ltd., Pilot Software, Sagent Technology, Inc., SAS Institute, Seagate Software, Silvon Software, Simba Technologies, Speedware Corporation, WhiteLight Systems, X-Tension. These vendors represent many facets of the data warehousing spectrum, and their support is indicative of the impact expected from the OLE DB for OLAP.
Q. Who can I contact to tell Microsoft that my product supports OLE DB for OLAP?
A. Vendors developing providers or consumers using OLE DB for OLAP should send e-mail to oledbinf@microsoft.com with detailed information about their company, a contact, and their product. Vendors should also indicate how OLE DB for OLAP will be used. A Microsoft representative will reply with information about publicizing your investment in our technology.