Class AbstractUnresolvedColumn

java.lang.Object
org.apache.drill.exec.physical.impl.scan.project.AbstractUnresolvedColumn
All Implemented Interfaces:
ColumnProjection
Direct Known Subclasses:
AbstractUnresolvedColumn.UnresolvedColumn, AbstractUnresolvedColumn.UnresolvedWildcardColumn, UnresolvedColumnsArrayColumn

public abstract class AbstractUnresolvedColumn extends Object implements ColumnProjection
Represents a projected column that has not yet been bound to a table column, special column or a null column. Once bound, this column projection is replaced with the detailed binding.

Occurs in a scan-level projection to identify columns needed in the output batch. Once we see reader data, we create a ResolvedColumn to replace this unresolved form. The resolved form identifies how to map data from its source (reader, null column builder, etc.) to the output batch. Thus the columns here are placeholders to be rewritten once more data is available.

  • Field Details

    • inCol

      protected final RequestedColumn inCol
      The original physical plan column to which this output column maps. In some cases, multiple output columns map map the to the same "input" (to the projection process) column.
  • Constructor Details

    • AbstractUnresolvedColumn

      public AbstractUnresolvedColumn(RequestedColumn inCol)
  • Method Details