org.apache.calcite.rel.metadata

Class RelMdCollation

java.lang.Object

org.apache.calcite.rel.metadata.RelMdCollation

All Implemented Interfaces:

MetadataHandler<BuiltInMetadata.Collation>

public class RelMdCollation
extends Object
implements MetadataHandler<BuiltInMetadata.Collation>

RelMdCollation supplies a default implementation of RelMetadataQuery.collations(org.apache.calcite.rel.RelNode) for the standard logical algebra.

Field Summary

Fields

Modifier and Type	Field and Description
static RelMetadataProvider	SOURCE

Method Summary

Modifier and Type	Method and Description
static List<RelCollation>	calc(RelMetadataQuery mq, RelNode input, RexProgram program) Helper method to determine a Calc's collation.
com.google.common.collect.ImmutableList<RelCollation>	collations(Calc calc, RelMetadataQuery mq)
com.google.common.collect.ImmutableList<RelCollation>	collations(EnumerableCorrelate join, RelMetadataQuery mq)
com.google.common.collect.ImmutableList<RelCollation>	collations(EnumerableHashJoin join, RelMetadataQuery mq)
com.google.common.collect.ImmutableList<RelCollation>	collations(EnumerableMergeJoin join, RelMetadataQuery mq)
com.google.common.collect.ImmutableList<RelCollation>	collations(EnumerableNestedLoopJoin join, RelMetadataQuery mq)
com.google.common.collect.ImmutableList<RelCollation>	collations(Filter rel, RelMetadataQuery mq)
com.google.common.collect.ImmutableList<RelCollation>	collations(HepRelVertex rel, RelMetadataQuery mq)
com.google.common.collect.ImmutableList<RelCollation>	collations(Match rel, RelMetadataQuery mq)
com.google.common.collect.ImmutableList<RelCollation>	collations(Project project, RelMetadataQuery mq)
com.google.common.collect.ImmutableList<RelCollation>	collations(RelNode rel, RelMetadataQuery mq) Catch-all implementation for BuiltInMetadata.Collation.collations(), invoked using reflection, for any relational expression not handled by a more specific method.
com.google.common.collect.ImmutableList<RelCollation>	collations(RelSubset rel, RelMetadataQuery mq)
com.google.common.collect.ImmutableList<RelCollation>	collations(SortExchange sort, RelMetadataQuery mq)
com.google.common.collect.ImmutableList<RelCollation>	collations(Sort sort, RelMetadataQuery mq)
com.google.common.collect.ImmutableList<RelCollation>	collations(TableModify rel, RelMetadataQuery mq)
com.google.common.collect.ImmutableList<RelCollation>	collations(TableScan scan, RelMetadataQuery mq)
com.google.common.collect.ImmutableList<RelCollation>	collations(Values values, RelMetadataQuery mq)
com.google.common.collect.ImmutableList<RelCollation>	collations(Window rel, RelMetadataQuery mq)
static List<RelCollation>	enumerableBatchNestedLoopJoin(RelMetadataQuery mq, RelNode left, RelNode right, JoinRelType joinType)
static List<RelCollation>	enumerableCorrelate(RelMetadataQuery mq, RelNode left, RelNode right, JoinRelType joinType)
static List<RelCollation>	enumerableHashJoin(RelMetadataQuery mq, RelNode left, RelNode right, JoinRelType joinType) Returns the collation of EnumerableHashJoin based on its inputs and the join type.
static List<RelCollation>	enumerableNestedLoopJoin(RelMetadataQuery mq, RelNode left, RelNode right, JoinRelType joinType) Returns the collation of EnumerableNestedLoopJoin based on its inputs and the join type.
static List<RelCollation>	enumerableSemiJoin(RelMetadataQuery mq, RelNode left, RelNode right)
static List<RelCollation>	filter(RelMetadataQuery mq, RelNode input) Helper method to determine a Filter's collation.
MetadataDef<BuiltInMetadata.Collation>	getDef()
static List<RelCollation>	limit(RelMetadataQuery mq, RelNode input) Helper method to determine a limit's collation.
static List<RelCollation>	match(RelMetadataQuery mq, RelNode input, RelDataType rowType, RexNode pattern, boolean strictStart, boolean strictEnd, Map<String,RexNode> patternDefinitions, Map<String,RexNode> measures, RexNode after, Map<String,? extends SortedSet<String>> subsets, boolean allRows, ImmutableBitSet partitionKeys, RelCollation orderKeys, RexNode interval) Helper method to determine a Match's collation.
static List<RelCollation>	mergeJoin(RelMetadataQuery mq, RelNode left, RelNode right, ImmutableIntList leftKeys, ImmutableIntList rightKeys) Helper method to determine a Join's collation assuming that it uses a merge-join algorithm.
static List<RelCollation>	project(RelMetadataQuery mq, RelNode input, List<? extends RexNode> projects) Helper method to determine a Project's collation.
static List<RelCollation>	snapshot(RelMetadataQuery mq, RelNode input) Helper method to determine a Snapshot's collation.
static List<RelCollation>	sort(RelCollation collation) Helper method to determine a Sort's collation.
static List<RelCollation>	table(RelOptTable table) Helper method to determine a TableScan's collation.
static List<RelCollation>	values(RelMetadataQuery mq, RelDataType rowType, com.google.common.collect.ImmutableList<com.google.common.collect.ImmutableList<RexLiteral>> tuples) Helper method to determine a Values's collation.
static List<RelCollation>	window(RelMetadataQuery mq, RelNode input, com.google.common.collect.ImmutableList<Window.Group> groups) Helper method to determine a Window's collation.

Methods inherited from class java.lang.Object

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

Field Detail

SOURCE

public static final RelMetadataProvider SOURCE

Method Detail

getDef

public MetadataDef<BuiltInMetadata.Collation> getDef()

Specified by:

getDef in interface MetadataHandler<BuiltInMetadata.Collation>

collations

public com.google.common.collect.ImmutableList<RelCollation> collations(RelNode rel,
                                                                        RelMetadataQuery mq)

Catch-all implementation for BuiltInMetadata.Collation.collations(), invoked using reflection, for any relational expression not handled by a more specific method.

Union, Intersect, Minus, Join, Correlate do not in general return sorted results (but implementations using particular algorithms may).

Parameters:

rel - Relational expression

Returns:

Relational expression's collations

See Also:

RelMetadataQuery.collations(RelNode)

collations

public com.google.common.collect.ImmutableList<RelCollation> collations(Window rel,
                                                                        RelMetadataQuery mq)

collations

public com.google.common.collect.ImmutableList<RelCollation> collations(Match rel,
                                                                        RelMetadataQuery mq)

collations

public com.google.common.collect.ImmutableList<RelCollation> collations(Filter rel,
                                                                        RelMetadataQuery mq)

collations

public com.google.common.collect.ImmutableList<RelCollation> collations(TableModify rel,
                                                                        RelMetadataQuery mq)

collations

public com.google.common.collect.ImmutableList<RelCollation> collations(TableScan scan,
                                                                        RelMetadataQuery mq)

collations

public com.google.common.collect.ImmutableList<RelCollation> collations(EnumerableMergeJoin join,
                                                                        RelMetadataQuery mq)

collations

public com.google.common.collect.ImmutableList<RelCollation> collations(EnumerableHashJoin join,
                                                                        RelMetadataQuery mq)

collations

public com.google.common.collect.ImmutableList<RelCollation> collations(EnumerableNestedLoopJoin join,
                                                                        RelMetadataQuery mq)

collations

public com.google.common.collect.ImmutableList<RelCollation> collations(EnumerableCorrelate join,
                                                                        RelMetadataQuery mq)

collations

public com.google.common.collect.ImmutableList<RelCollation> collations(Sort sort,
                                                                        RelMetadataQuery mq)

collations

public com.google.common.collect.ImmutableList<RelCollation> collations(SortExchange sort,
                                                                        RelMetadataQuery mq)

collations

public com.google.common.collect.ImmutableList<RelCollation> collations(Project project,
                                                                        RelMetadataQuery mq)

collations

public com.google.common.collect.ImmutableList<RelCollation> collations(Calc calc,
                                                                        RelMetadataQuery mq)

collations

public com.google.common.collect.ImmutableList<RelCollation> collations(Values values,
                                                                        RelMetadataQuery mq)

collations

public com.google.common.collect.ImmutableList<RelCollation> collations(HepRelVertex rel,
                                                                        RelMetadataQuery mq)

collations

public com.google.common.collect.ImmutableList<RelCollation> collations(RelSubset rel,
                                                                        RelMetadataQuery mq)

table

public static List<RelCollation> table(RelOptTable table)

Helper method to determine a TableScan's collation.

snapshot

public static List<RelCollation> snapshot(RelMetadataQuery mq,
                                          RelNode input)

Helper method to determine a Snapshot's collation.

sort

public static List<RelCollation> sort(RelCollation collation)

Helper method to determine a Sort's collation.

filter

public static List<RelCollation> filter(RelMetadataQuery mq,
                                        RelNode input)

Helper method to determine a Filter's collation.

limit

public static List<RelCollation> limit(RelMetadataQuery mq,
                                       RelNode input)

Helper method to determine a limit's collation.

calc

public static List<RelCollation> calc(RelMetadataQuery mq,
                                      RelNode input,
                                      RexProgram program)

Helper method to determine a Calc's collation.

project

public static List<RelCollation> project(RelMetadataQuery mq,
                                         RelNode input,
                                         List<? extends RexNode> projects)

Helper method to determine a Project's collation.

window

public static List<RelCollation> window(RelMetadataQuery mq,
                                        RelNode input,
                                        com.google.common.collect.ImmutableList<Window.Group> groups)

Helper method to determine a Window's collation.

A Window projects the fields of its input first, followed by the output from each of its windows. Assuming (quite reasonably) that the implementation does not re-order its input rows, then any collations of its input are preserved.

match

public static List<RelCollation> match(RelMetadataQuery mq,
                                       RelNode input,
                                       RelDataType rowType,
                                       RexNode pattern,
                                       boolean strictStart,
                                       boolean strictEnd,
                                       Map<String,RexNode> patternDefinitions,
                                       Map<String,RexNode> measures,
                                       RexNode after,
                                       Map<String,? extends SortedSet<String>> subsets,
                                       boolean allRows,
                                       ImmutableBitSet partitionKeys,
                                       RelCollation orderKeys,
                                       RexNode interval)

Helper method to determine a Match's collation.

values

public static List<RelCollation> values(RelMetadataQuery mq,
                                        RelDataType rowType,
                                        com.google.common.collect.ImmutableList<com.google.common.collect.ImmutableList<RexLiteral>> tuples)

Helper method to determine a Values's collation.

We actually under-report the collations. A Values with 0 or 1 rows - an edge case, but legitimate and very common - is ordered by every permutation of every subset of the columns.

So, our algorithm aims to:

• produce at most N collations (where N is the number of columns);
• make each collation as long as possible;
• do not repeat combinations already emitted - if we've emitted (a, b) do not later emit (b, a);
• probe the actual values and make sure that each collation is consistent with the data

So, for an empty Values with 4 columns, we would emit (a, b, c, d), (b, c, d), (c, d), (d).

mergeJoin

public static List<RelCollation> mergeJoin(RelMetadataQuery mq,
                                           RelNode left,
                                           RelNode right,
                                           ImmutableIntList leftKeys,
                                           ImmutableIntList rightKeys)

Helper method to determine a Join's collation assuming that it uses a merge-join algorithm.

If the inputs are sorted on other keys in addition to the join key, the result preserves those collations too.

enumerableHashJoin

public static List<RelCollation> enumerableHashJoin(RelMetadataQuery mq,
                                                    RelNode left,
                                                    RelNode right,
                                                    JoinRelType joinType)

Returns the collation of EnumerableHashJoin based on its inputs and the join type.

enumerableNestedLoopJoin

public static List<RelCollation> enumerableNestedLoopJoin(RelMetadataQuery mq,
                                                          RelNode left,
                                                          RelNode right,
                                                          JoinRelType joinType)

Returns the collation of EnumerableNestedLoopJoin based on its inputs and the join type.

enumerableCorrelate

public static List<RelCollation> enumerableCorrelate(RelMetadataQuery mq,
                                                     RelNode left,
                                                     RelNode right,
                                                     JoinRelType joinType)

enumerableSemiJoin

public static List<RelCollation> enumerableSemiJoin(RelMetadataQuery mq,
                                                    RelNode left,
                                                    RelNode right)

enumerableBatchNestedLoopJoin

public static List<RelCollation> enumerableBatchNestedLoopJoin(RelMetadataQuery mq,
                                                               RelNode left,
                                                               RelNode right,
                                                               JoinRelType joinType)