OLAP allows complex, multidimensional queries over large datasets to be rapidly answered. An OLAP system models the world as facts representing quantitative or qualitative measurements of things of interest. This article defines the different types and their pros and cons.
Products
History
The first product that performed OLAP queries was Express, which was released in 1970 (and acquired by Oracle in 1995 from Information Resources). However, the term did not appear until 1993 when it was coined by Edgar F. Codd, who has been described as "the father of the relational database". Codd's paper resulted from a short consulting assignment which Codd undertook for former Arbor Software (later Hyperion Solutions, and in 2007 acquired by Oracle), as a sort of marketing coup. The company had released its own OLAP product, Essbase, a year earlier. As a result, Codd's "twelve laws of online analytical processing" were explicit in their reference to Essbase. There was some ensuing controversy and when Computerworld learned that Codd was paid by Arbor, it retracted the article. OLAP market experienced strong growth in late 1990s with dozens of commercial products going into market. In 1998, Microsoft released its first OLAP Server – Microsoft Analysis Services, which drove wide adoption of OLAP technology and moved it into mainstream.
Product comparison
OLAP clients
OLAP clients include many spreadsheet programs like Excel, web application, SQL,dashboard tools, etc. Many clients support interactive data exploration where users select dimensions and measures of interest. Some dimensions are used as filters (for slicing and dicing the data) while others are selected as the axes of a pivot table or pivot chart. Users can also vary aggregation level (for drilling-down or rolling-up) the displayed view. Clients can also offer a variety of graphical widgets such as sliders, geographic maps, heatmaps and more which can be grouped and coordinated as dashboards. An extensive list of clients appears in the visualization column of the comparison of OLAP servers table.
Market structure
Below is a list of top OLAP vendors in 2006, with figures in millions of US Dollars.
Vendor | Global Revenue | Consolidated company |
---|---|---|
Microsoft Corporation | 1,806 | Microsoft |
Hyperion Solutions Corporation | 1,077 | Oracle |
Cognos | 735 | IBM |
Business Objects | 416 | SAP |
MicroStrategy | 416 | MicroStrategy |
SAP AG | 330 | SAP |
Cartesis (SAP) | 210 | SAP |
Applix | 205 | IBM |
Infor | 199 | Infor |
Oracle Corporation | 159 | Oracle |
Others | 152 | Others |
Total | 5,700 |
Open-source
- Mondrian OLAP server is an open-source OLAP server written in Java. It supports the MDX query language, the XML for Analysis and the olap4j interface specifications.
- Druid (open-source data store) is a popular open-source distributed data store for OLAP queries that is used at scale in production by various organizations.
- Apache Kylin is a distributed data store for OLAP queries originally developed by eBay.
- Cubes (OLAP server) is another light-weight open-source toolkit implementation of OLAP functionality in the Python programming language with built-in ROLAP.
- Apache Pinot (incubating) is used at LinkedIn, Uber, Slack and Microsoft to deliver scalable real time analytics with low latency. It can ingest data from offline data sources (such as Hadoop and flat files) as well as online sources (such as Kafka). Pinot is designed to scale horizontally.