=============== Complex Queries =============== .. rubric:: Table of contents .. contents:: :local: :depth: 2 Besides simple SFW queries (SELECT-FROM-WHERE), there is also support for complex queries such as Subquery, ``JOIN``, ``UNION`` and ``MINUS``. For these queries, more than one OpenSearch index and DSL query is involved. You can check out how they are performed behind the scene by our explain API.