You can define context variables from the Profiling perspective to connect to data sources and decide to run an analysis with a specific context.
The Profiling perspective of Talend Studio allows you to define multiple context parameters for any of the database or file connections you define in the Metadata node in the DQ Repository tree view. Then you can select a specific context parameters with which you want to execute one or more of the analyses that use the database or the file connection. For example, there might be various testing stages you want to perform and validate before an analysis is ready to go for production use.
While setting the connection information for a database or a file as outlined in Connecting to a database or in Connecting to a file respectively, you can export the connection as a context and centralize it under the Context node in the Integration perspective of your Studio. You can reuse this context in the data quality analyses that use the current connection. You can also create different context parameters for the same connection and later choose to execute an analysis on one specific context.
For detailed information on centralizing contexts and variables to be used in data integration Jobs or data quality analyses, see Centralizing database metadata.