com>
Sent: Tuesday, December 22, 2015 12:52 AM
To: Roland Reumerman
Cc: dev@spark.apache.org
Subject: Re: Expression/LogicalPlan dichotomy in Spark SQL Catalyst
Why was the choice made in Catalyst to make LogicalPlan/QueryPlan and
Expression separate subclasses of TreeNode, instead of e.g. als
>
> Why was the choice made in Catalyst to make LogicalPlan/QueryPlan and
> Expression separate subclasses of TreeNode, instead of e.g. also make
> QueryPlan inherit from Expression?
>
I think this is a pretty common way to model things (glancing at postgres
it looks similar). Expression and
[Note: this question has been moved from the Conversation in
[SPARK-4226][SQL]Add subquery (not) in/exists support #9055
to the dev mailing list.]
We've added our own In/Exists - plus Subquery in Select - support to a partial
fork of Spark SQL Catalyst (which we use in transformations from
