Package org.apache.flink.table.planner.plan.metadata

Interface FlinkMetadata.ColumnNullCount

All Superinterfaces:
org.apache.calcite.rel.metadata.Metadata
Enclosing class:
FlinkMetadata
public static interface FlinkMetadata.ColumnNullCount extends org.apache.calcite.rel.metadata.Metadata
Metadata about the null count of given column from a specified relational expression.

  • Nested Class Summary

    Nested Classes
    Modifier and Type
    Interface
    Description
    static interface 
    FlinkMetadata.ColumnNullCount.Handler
    Handler API.

  • Field Summary

    Fields
    Modifier and Type
    Field
    Description
    static final org.apache.calcite.rel.metadata.MetadataDef<FlinkMetadata.ColumnNullCount>
    DEF
     
    static final Method
    METHOD
     

  • Method Summary

    Modifier and Type
    Method
    Description
    Double
    getColumnNullCount(int index)
    Returns the null count of the given column from a specified relational expression.

    Methods inherited from interface org.apache.calcite.rel.metadata.Metadata

    rel

  • Field Details

  • Method Details

    • getColumnNullCount

      Double getColumnNullCount(int index)
      Returns the null count of the given column from a specified relational expression.
      Parameters:
      index - the index of the given column in a specified relational expression
      Returns:
      the null count of the given column if can be estimated, else return null.