Add a comment about ColumnStatistics' "unknown" estimates semantics
@@ -114,6 +114,12 @@ public final class ColumnStatistics
return new Builder();
}
+ /**
+ * If one of the estimates below is unspecified, the default "unknown" estimate value
+ * (represented by floating point NaN) may cause the resulting symbol statistics
+ * to be "unknown" as well.
+ * @see SymbolStatsEstimate
+ */
public static final class Builder
{
private Estimate nullsFraction = Estimate.unknown();
