While working on Solr and Calcite integration, I found that there is a case where some tools issue a sql query like "where 1 = 0" just to get metadata information back. Spark SQL is one of the ones that does this.
Calcite doesn't seem to optimize away the literal comparison literal case with RexUtil.simplify. In my understanding any literal comparison literal results in a simple TRUE/FALSE result. I'm not sure this is valid in the general case, but I put together a simple example of doing this on the RexUtil simplifyCall. https://github.com/apache/calcite/pull/376 I would love to hear any feedback related to this. I need to run through the full Calcite test suite, but wondering if this is even viable. Thanks! Kevin Risden
