Pushdown filter in prepared statement

[Chin Wei Low]

Hi,

I am implementing a calcite adapter, and created a rule to pushdown filter.
When I execute a prepared statement, I can see the condition contains a
RexDynamicParam with value "?0" in the LogicalFilter.
How can I get the value of the bind variable, so I can push it down to the
underlying data source.

Regards,
Chin Wei