Package org.apache.calcite.rel

Class RelCollations

java.lang.Object

org.apache.calcite.rel.RelCollations

public class RelCollations
extends Object

Utilities concerning RelCollation and RelFieldCollation.

Field Summary

Fields

Modifier and Type	Field	Description
static final RelCollation	EMPTY	A collation indicating that a relation is not sorted.
static final RelCollation	PRESERVE	Deprecated.

Method Summary

Modifier and Type	Method	Description
static boolean	collationsContainKeysOrderless(List<RelCollation> collations, List<Integer> keys)	Returns whether one of a list of collations contains the given list of keys regardless the order.
static boolean	contains(List<RelCollation> collations, ImmutableIntList keys)	Returns whether one of a list of collations indicates that the collection is sorted on the given list of keys.
static boolean	contains(RelCollation collation, Iterable<Integer> keys)	Returns whether a collation indicates that the collection is sorted on a given list of keys.
static boolean	containsOrderless(List<Integer> keys, RelCollation collation)	Returns whether a collation is contained by a given list of keys regardless ordering.
static boolean	containsOrderless(RelCollation collation, List<Integer> keys)	Returns whether a collation contains a given list of keys regardless the order.
static List<RelCollation>	createSingleton(int fieldIndex)	Creates a list containing one collation containing one field.
static boolean	equal(List<RelCollation> collationList1, List<RelCollation> collationList2)
static boolean	isValid(RelDataType rowType, List<RelCollation> collationList, boolean fail)	Checks that a collection of collations is valid.
static boolean	keysContainCollationsOrderless(List<Integer> keys, List<RelCollation> collations)	Returns whether one of a list of collations is contained by the given list of keys regardless the order.
static RelCollation	of(int fieldIndex)	Creates a collation containing one field.
static RelCollation	of(List<RelFieldCollation> fieldCollations)
static RelCollation	of(RelFieldCollation... fieldCollations)
static RelCollation	of(ImmutableIntList keys)	Creates a collation containing multiple fields.
static List<Integer>	ordinals(List<RelFieldCollation> fieldCollations)	Returns the indexes of the fields in a list of field collations.
static List<Integer>	ordinals(RelCollation collation)	Returns the indexes of the field collations in a given collation.
static RelCollation	permute(RelCollation collation, Map<Integer,Integer> mapping)	Creates a copy of this collation that changes the ordinals of input fields.
static RelCollation	permute(RelCollation collation, Mappings.TargetMapping mapping)	Creates a copy of this collation that changes the ordinals of input fields.
static RelCollation	shift(RelCollation collation, int offset)

Methods inherited from class java.lang.Object

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

Field Details

EMPTY

public static final RelCollation EMPTY

A collation indicating that a relation is not sorted. Ordering by no columns.

PRESERVE

@Deprecated
public static final RelCollation PRESERVE

Deprecated.

A collation that cannot be replicated by applying a sort. The only implementation choice is to apply operations that preserve order.

Method Details

of

public static RelCollation of(RelFieldCollation... fieldCollations)

of

public static RelCollation of(List<RelFieldCollation> fieldCollations)

of

public static RelCollation of(int fieldIndex)

Creates a collation containing one field.

of

public static RelCollation of(ImmutableIntList keys)

Creates a collation containing multiple fields.

createSingleton

public static List<RelCollation> createSingleton(int fieldIndex)

Creates a list containing one collation containing one field.

isValid

public static boolean isValid(RelDataType rowType,
 List<RelCollation> collationList,
 boolean fail)

Checks that a collection of collations is valid.

Parameters:

rowType - Row type of the relational expression

collationList - List of collations

fail - Whether to fail if invalid

Returns:

Whether valid

equal

public static boolean equal(List<RelCollation> collationList1,
 List<RelCollation> collationList2)

ordinals

public static List<Integer> ordinals(RelCollation collation)

Returns the indexes of the field collations in a given collation.

ordinals

public static List<Integer> ordinals(List<RelFieldCollation> fieldCollations)

Returns the indexes of the fields in a list of field collations.

contains

public static boolean contains(RelCollation collation,
 Iterable<Integer> keys)

Returns whether a collation indicates that the collection is sorted on a given list of keys.

Parameters:

collation - Collation

keys - List of keys

Returns:

Whether the collection is sorted on the given keys

contains

public static boolean contains(List<RelCollation> collations,
 ImmutableIntList keys)

Returns whether one of a list of collations indicates that the collection is sorted on the given list of keys.

containsOrderless

public static boolean containsOrderless(RelCollation collation,
 List<Integer> keys)

Returns whether a collation contains a given list of keys regardless the order.

Parameters:

collation - Collation

keys - List of keys

Returns:

Whether the collection contains the given keys

containsOrderless

public static boolean containsOrderless(List<Integer> keys,
 RelCollation collation)

Returns whether a collation is contained by a given list of keys regardless ordering.

Parameters:

keys - List of keys

collation - Collation

Returns:

Whether the collection contains the given keys

collationsContainKeysOrderless

public static boolean collationsContainKeysOrderless(List<RelCollation> collations,
 List<Integer> keys)

Returns whether one of a list of collations contains the given list of keys regardless the order.

keysContainCollationsOrderless

public static boolean keysContainCollationsOrderless(List<Integer> keys,
 List<RelCollation> collations)

Returns whether one of a list of collations is contained by the given list of keys regardless the order.

shift

public static RelCollation shift(RelCollation collation,
 int offset)

permute

public static RelCollation permute(RelCollation collation,
 Map<Integer,Integer> mapping)

Creates a copy of this collation that changes the ordinals of input fields.

permute

public static RelCollation permute(RelCollation collation,
 Mappings.TargetMapping mapping)

Creates a copy of this collation that changes the ordinals of input fields.