Yes, this is exactly what Calcite is intended for. Those limitations are out of date. The JDBC adapter can push down all of the standard relational operators (exceptions being NULLS FIRST/LAST, GROUPING SETS and maybe window functions).
You will need a schema adapter (i.e. a class that implements SchemaFactory) for each of those kinds of data. > - Databases by JDBC Use JdbcSchema.Factory. This is so common that in a model.json you can just say "type": "JDBC" > - REST Services We have a prototype web adapter; see https://issues.apache.org/jira/browse/CALCITE-884. > - SOLR Search by SolrJ There is no SOLR (or Lucene) adapter currently. > - POJO You can build schemas on POJOs - see ReflectiveSchema - but there is no SchemaFactory, so you need to instantiate the schema manually. Julian
