[plug-ins] AbstractGroupScan.getScanStats()

[Daniel Barclay <db...@maprtech.com>]

Somewhat (although not exactly) similarly to the case below, AbstractGroupScan has an implementation of GroupScan.clone(List<SchemaPath>), but that implementation doesn't do anything other than throw an exception:

    throw new UnsupportedOperationException(String.format("%s does not implement clone(columns) method!", this.getClass().getCanonicalName()));

Is there any need for AbstractGroupScan to declare a non-abstract clone(List<SchemaPath>)?  Is there any need for it to re-declare clone(List<SchemaPath>)at all?  (Does it narrow the contract?)

Daniel

I wrote:
> Method org.apache.drill.exec.physical.base.AbstractGroupScan.getScanStats()
> has a body that throws a "This must be implemented" exception.
>
> Why isn't getScanStats()simply an abstract method?
>
> (Is there any case in which a subclass doesn't need to implement the
> method (i.e., where that method won't ever be called for that subclass)?)
>
>
> Daniel


-- 
Daniel Barclay
MapR Technologies