Extension:Semantic OLAP

MediaWiki extensions manual
Semantic OLAP
Release status: unmaintained
Implementation Ajax, Special page , Data extraction
Description Analyse data in Semantic MediaWiki by using OLAP functionality
Author(s) Tobias Wellertalk
Latest version 1.0 (2017-06-12)
MediaWiki 1.19+
PHP 5.3+
Database changes No
License MIT License

Semantic OLAP is an extension to Semantic MediaWiki that allows to query and analyse data, stored in the semantic MediaWiki, by using OLAP functionality. Users can analyse the data from different views by changing the pivot table. Semantic OLAP uses orbjs, which is based on React.js, to customize and control the pivot table.


The Semantic MediaWiki extension must be installed in order to use this extension.
  • Download, extract and place the file(s) in a directory called SemanticOLAP in your extensions/ folder.
  • Add the following code at the bottom of your LocalSettings.php file:
    wfLoadExtension( 'SemanticOLAP' );
  •   Done – Navigate to Special:Version on your wiki to verify that the extension is successfully installed.



Select Data


In the initial screen of the Semantic OLAP Special Page, the data that should be queried must be selected.

  • At least one Category and one Property must be selected.
  • Autocomplete simplifies the input and suggests available Categories and Properties

On the basis of the input, a simple ASK Query is created in the background. If no result is returned, a Popup appears with the corresponding ASK query.


Analyse Data


Tool allows to analyse the data by using OLAP functionality.

  • Use Drag&Drop to change the view on the pivot table
  • If multiple values are linked to the same Property then only the first Value is selected.
  • If a property is of type "Quantity", the corresponding unit is displayed.
  • Click on "Select Data" to get back to the initial screen and select the data for analysis


Filter and Sort Values


Semantic OLAP allows to filter for values. In order to filter, click on the right icon on the corresponding property and filter vor values either by

  • Matches (i.e. greater than, lower than)
  • Tick the concrete values


Export Data


The current view on the data is downloaded in spreadsheet format by clicking on the export xls button.


Future Work

  • Select aggregation function (sum, avg, max, min)
    • Currently, only sum is available
  • Advanced ASK Queries/Selection of data
  • Allow to display information in graphs



- Include the Semantic OLAP into a page

See also

Link to authors
Link to information pages