Dear Apache Calcite Team, I am trying to learn Calcite and wish to build a poc for data federation.
In the video here, https://www.youtube.com/watch?v=4JAOkLKrcYE, somehow the presenter and his team managed to squash parts of the Relational Nodes into "Spark Tables" and then Spark handled the execution of those. How do I exactly go about doing this? As per this discussion I understand that one has to create a RelOptRule to do the same. Also, one has to somehow define the cost (I don't know how to do this). Is there a simple tutorial which demonstrates the basics of this? Like some kind of simple implementation with ListTable etc. Thanks & Regards, Pranav
