Package org.apache.calcite.materialize

Interface LatticeStatisticProvider

All Known Implementing Classes:

DelegatingLatticeStatisticProvider

public interface LatticeStatisticProvider

Estimates row counts for a lattice and its attributes.

Nested Class Summary

Nested Classes

Modifier and Type	Interface	Description
static interface	LatticeStatisticProvider.Factory	Creates a LatticeStatisticProvider for a given Lattice.

Method Summary

Modifier and Type	Method	Description
double	cardinality(List<Lattice.Column> columns)	Returns an estimate of the number of distinct values in a column or list of columns.

Method Details

cardinality

double cardinality(List<Lattice.Column> columns)

Returns an estimate of the number of distinct values in a column or list of columns.