Qlik Big Data Index Selector
The QBDI Selector provides access to a big data source that has been indexed with Qlik Big Data Index. The Selector connects to big data sources through an interface that is similar to other Qlik connectors, such as ODBC. For data selection, the Selector uses Qlik Sense field selectors with the full green-white-grey inference model to browse and select from the full set of fields in an indexed data source.
The QBDI Selector is built into Qlik Sense. It appears in the list of data sources in the Data load editor. From there, Qlik Sense app developers use it to load traditional Qlik in-memory apps. When data is selected, the app's load script queries just the subset of tables, fields, and rows selected by the user to produce a data model of the subset of indexed data.
By using Qlik Big Data Index to index the Parquet files in the data source, a full index of all the data in the Parquet "data lake" can be created and used over the complete data set. The QBDI Selector allows users to interact with the data using Qlik Sense field-selection controls to quickly identify specific subsets of data that meet the application's requirements. Each subset is fully connected across the model tables because the model's associations have been indexed. In this way, the Selector provides a Qlik "associative" experience to rapidly identify a connected subset of records from a large, enterprise data lake.
While the Selector interface appears and acts like a Qlik app, it uses Qlik Big Data Index to perform the data inferences required to properly populate the field selection list boxes it exposes to the user. Internally, to answer the selection queries, the Qlik associative engine submits Qlik Selection Language (QSL) queries through the connection between the engine and the Query Manager component of Qlik Big Data Index.
Once the user has made the selections needed to identify the subset of data to load, the Selector generates a block of Qlik script that performs a series of QSL queries involving:
- the exact subset of tables selected
- the exact subset of fields selected
- the subset of records from the chosen tables via the current selection state