Class RelMdExpressionLineage

java.lang.Object
org.apache.calcite.rel.metadata.RelMdExpressionLineage
All Implemented Interfaces:
MetadataHandler<BuiltInMetadata.ExpressionLineage>

public class RelMdExpressionLineage
extends Object
implements MetadataHandler<BuiltInMetadata.ExpressionLineage>
Default implementation of RelMetadataQuery.getExpressionLineage(org.apache.calcite.rel.RelNode, org.apache.calcite.rex.RexNode) for the standard logical algebra.

The goal of this provider is to infer the lineage for the given expression.

The output expressions might contain references to columns produced by TableScan operators (RexTableInputRef). In turn, each TableScan operator is identified uniquely by a RexTableInputRef.RelTableRef containing its qualified name and an identifier.

If the lineage cannot be inferred, we return null.