Microsoft Analysis Services


Microsoft SQL Server Analysis Services, SSAS, is an online analytical processing and data mining tool in Microsoft SQL Server. SSAS is used as a tool by organizations to analyze and make sense of information possibly spread out across multiple databases, or in disparate tables or files. Microsoft has included a number of services in SQL Server related to business intelligence and data warehousing. These services include Integration Services, Reporting Services and Analysis Services. Analysis Services includes a group of OLAP and data mining capabilities and comes in two flavors - Multidimensional and Tabular.

History

In 1996, Microsoft began its foray into the OLAP Server business by acquiring the OLAP software technology from Canada-based Panorama Software.
Just over two years later, in 1998, Microsoft released OLAP Services as part of SQL Server 7. OLAP Services supported MOLAP, ROLAP, and HOLAP architectures, and it used OLE DB for OLAP as the client access API and MDX as a query language. It could work in client-server mode or offline mode with local cube files.
In 2000, Microsoft released Analysis Services 2000. It was renamed from "OLAP Services" due to the inclusion of data mining services. Analysis Services 2000 was considered an evolutionary release, since it was built on the same architecture as OLAP Services and was therefore backward compatible with it. Major improvements included more flexibility in dimension design through support of parent child dimensions, changing dimensions, and virtual dimensions. Another feature was a greatly enhanced calculation engine with support for unary operators, custom rollups, and cell calculations. Other features were dimension security, distinct count, connectivity over HTTP, session cubes, grouping levels, and many others.
In 2005, Microsoft released the next generation of OLAP and data mining technology as Analysis Services 2005. It maintained backward compatibility on the API level: although applications written with OLE DB for OLAP and MDX continued to work, the architecture of the product was completely different. The major change came to the model in the form of UDM - Unified Dimensional Model.

Timeline

The key events in the history of Microsoft Analysis Services cover a period starting in 1996.
DateEvent
1996-07-01Microsoft opens new team to build an OLAP product, codenamed Plato
1996-07-15Panorama Software delegation meets with Microsoft
1996-10-27Microsoft announces acquisition of Panorama Software development team
1998-11OLAP Services 7.0 ships
2000-08Analysis Services 2000 ships
2001-11XML for Analysis Software Development Kit 1.0 ships
2003-04ADOMD.NET and XML for Analysis SDK 1.1 ship
2005-10-28Analysis Services 2005 ships
2008-08-06Analysis Services 2008 ships
2012-03-06Analysis Services 2012
2014-04-01Analysis Services 2014
2016-06-01Analysis Services 2016

Multidimensional Storage modes

Microsoft Analysis Services takes a neutral position in the MOLAP vs. ROLAP arguments among OLAP products.
It allows all the flavors of MOLAP, ROLAP and HOLAP to be used within the same model.

Partition storage modes

Microsoft Analysis Services supports different sets of APIs and object models for different operations and in different programming environments.

Querying

Microsoft Analysis Services supports the following query languages

[Data definition language] (DDL)

DDL in Analysis Services is XML based and supports commands such as , , , and .
For data mining models import and export, it also supports PMML.

[Data manipulation language] (DML)

  • MDX - for querying OLAP cubes
  • LINQ - for querying OLAP cubes from.NET using ADO.NET Entity Framework and Language INtegrated Query
  • SQL - small subset of SQL for querying OLAP cubes and dimensions as if they were tables
  • DMX - for querying Data Mining models
  • DAX - for querying Tabular models