Package org.apache.drill.metastore.statistics

Interface Histogram

All Known Implementing Classes:
NumericEquiDepthHistogram
public interface Histogram
A column specific histogram

  • Method Summary

    Modifier and Type
    Method
    Description
    Double
    estimatedSelectivity(org.apache.calcite.rex.RexNode filter, long totalRowCount, long ndv)
    For a filter condition, estimate the selectivity (matching rows/total rows) for this histogram.

  • Method Details

    • estimatedSelectivity

      Double estimatedSelectivity(org.apache.calcite.rex.RexNode filter, long totalRowCount, long ndv)
      For a filter condition, estimate the selectivity (matching rows/total rows) for this histogram.
      Returns:
      estimated selectivity or NULL if it could not be estimated for any reason