Dear Apache Calcite Team, I have 2 questions. --------------------------------- 1.
There are plenty of examples on how to push down projects and filters into the leaf nodes (tablescans). However, I could not find any examples to push down joins to TableScans (or joins+filters+projects etc.) [this is helpful for data federation I think]. On the mailing list, many folks are suggesting that I use Drill. However, the purpose of my exercise is to gain knowledge about DBMS and Query processing etc. I tried debugging open source engines that use Calcite (Drill, Druid, Trino etc.) but was completely lost. Any examples/pointers/guidance around the same would be appreciated. Example, pushing down a join with a filter to a DBMS(consider jdbc msql etc.) ------------------------------------- 2. The 2nd question I have is regarding conventions and different DBMS. The cluster has a method to replace the trait convention(Bindable,JDBC etc.), and then we optimize and get the physical plan. But imagine I have both the MYSQL JDBC convnction and a cassandra convention and some user is trying to query both tables. Something like "SELECT users.username, specialdata.country from cassandraDB.user join mysqlDB.specialdata ON users.id=specialdata.userid" Now, how will calcite do the optimization here? The planner is not accepting 2 different conventions. Thanks & Regards, Pranav
