Class RexTableInputRef

  • public class RexTableInputRef
    extends RexInputRef
    Variable which references a column of a table occurrence in a relational plan.

    This object is used by BuiltInMetadata.ExpressionLineage and BuiltInMetadata.AllPredicates.

    Given a relational expression, its purpose is to be able to reference uniquely the provenance of a given expression. For that, it uses a unique table reference (contained in a RexTableInputRef.RelTableRef) and an column index within the table.

    For example, A.#0.$3 + 2 column $3 in the 0 occurrence of table A in the plan.

    Note that this kind of RexNode is an auxiliary data structure with a very specific purpose and should not be used in relational expressions.