I want to build a RelNode tree with different conventions on different RelNodes
(for example: in the following select query "select * from t1,t2", t1 is a
table from Oracle and t2 is a table from SqlServer).
I'm confused whether i should be using a single SchemaPlus to hold table
references from both Oracle and SqlServer or I should be creating a different
SchemaPlus for each product. Different SchemaPlus would force me to use a
different RelBuilder, so my guess is that a single SchemaPlus with the
following hierarchy may suffice ("oracle" -> "database1" -> "schema1" -> "t1").
However, I suspect this single hierarchy (with the product name inside) may not
play well with other parts of Calcite.
Any thoughts, however small would be appreciated.