Techniques are described for an interactive query service that enables users to query data stored at a federated collection of data sources. An interactive query service provides interfaces that enable users to configure the interactive query service to query any number of heterogeneous data sources pertinent to a user. In general, the configuration of a data source can include identification of: a data source type, access configurations related to accessing the data source, and in some cases metadata describing a structure of the data stored by the data source (for example, a data catalog describing schemas, tables, columns, partitions, datatypes, or other metadata associated with the stored data). Once configured, an interactive query service can receive and execute queries that involve data stored at any combination of a user's data sources, where the queries may be expressed using a standard query language such as the Structured Query Language (SQL).