org.apache.calcite.materialize

Class LatticeSuggester

java.lang.Object

org.apache.calcite.materialize.LatticeSuggester

public class LatticeSuggester
extends Object

Algorithm that suggests a set of lattices.

Constructor Summary

Constructors

Constructor and Description
LatticeSuggester(FrameworkConfig config) Creates a LatticeSuggester.

Method Summary

Modifier and Type	Method and Description
List<Lattice>	addQuery(RelNode r) Adds a query.
Set<Lattice>	getLatticeSet() Returns the minimal set of lattices necessary to cover all of the queries seen.
RexNode	toRex(LatticeTable table, int column) Converts a column reference to an expression.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

LatticeSuggester

public LatticeSuggester(FrameworkConfig config)

Creates a LatticeSuggester.

Method Detail

getLatticeSet

public Set<Lattice> getLatticeSet()

Returns the minimal set of lattices necessary to cover all of the queries seen. Any lattices that are subsumed by other lattices are not included.

toRex

public RexNode toRex(LatticeTable table,
                     int column)

Converts a column reference to an expression.

addQuery

public List<Lattice> addQuery(RelNode r)

Adds a query.

It may fit within an existing lattice (or lattices). Or it may need a new lattice, or an extension to an existing lattice.

Parameters:

r - Relational expression for a query

Returns:

A list of join graphs: usually 1; more if the query contains a cartesian product; zero if the query graph is cyclic