com.bigdata.rdf.spo

Class SPOKeyOrder

java.lang.Object

com.bigdata.striterator.AbstractKeyOrder<ISPO>

com.bigdata.rdf.spo.SPOKeyOrder

All Implemented Interfaces:

IKeyOrder<ISPO>, Serializable

public class SPOKeyOrder
extends AbstractKeyOrder<ISPO>
implements Serializable

Represents the key order used by an index for a triple relation.

Author:

Bryan Thompson

See Also:

Serialized Form

Field Summary

Fields

Modifier and Type	Field and Description
static int	_CSPO
static int	_OCSP
static int	_OSP
static int	_PCSO
static int	_POCS
static int	_POS
static int	_SOPC
static int	_SPO
static int	_SPOC
static int	C
static SPOKeyOrder	CSPO
static int	FIRST_QUAD_INDEX
static int	FIRST_TRIPLE_INDEX
static int	LAST_QUAD_INDEX
static int	LAST_TRIPLE_INDEX
static int	MAX_INDEX_COUNT
static int	O
static SPOKeyOrder	OCSP
static SPOKeyOrder	OSP
static int	P
static SPOKeyOrder	PCSO
static SPOKeyOrder	POCS
static SPOKeyOrder	POS
static int	S
static SPOKeyOrder	SOPC
static SPOKeyOrder	SPO
static SPOKeyOrder	SPOC

Method Summary

Methods

Modifier and Type	Method and Description
IKeyBuilder	appendKey(IKeyBuilder keyBuilder, ISPO spo) Appends the key for a given index order into the IKeyBuilder.
protected void	appendKeyComponent(IKeyBuilder keyBuilder, int index, Object keyComponent) Encodes an value into the key.
SPO	decodeKey(byte[] key) Decode the key into an SPO.
SPO	decodeKey(byte[] key, int offset) Decode the key into an SPO.
byte[]	encodeKey(IKeyBuilder keyBuilder, ISPO spo) Forms the key for a given index order (the SPOTupleSerializer delegates its behavior to this method).
static SPOKeyOrder	fromString(String name) Covert a name of an SPOKeyOrder into an SPOKeyOrder.
Comparator<ISPO>	getComparator() Return the comparator that places ISPOs into the natural order for the associated index.
byte[]	getFromKey(IKeyBuilder keyBuilder, IPredicate<ISPO> predicate) Return the inclusive lower bound which would be used for a query against this IKeyOrder for the given IPredicate.
String	getIndexName() The base name for the index.
int	getKeyArity() Return either 3 or 4 depending on the #of components in the key for this natural key ordering.
int	getKeyOrder(int keyPos) Return the index of the slot in the ISPO tuple which appears at the specified position in the key.
static SPOKeyOrder	getKeyOrder(IPredicate<ISPO> predicate, int keyArity) Return the SPOKeyOrder for the given predicate.
int	getPositionInIndex(int spoIdentifier) Returns the position of the given spoIdentifier in the index.
byte[]	getToKey(IKeyBuilder keyBuilder, IPredicate<ISPO> predicate) Return the exclusive upper bound which would be used for a query against this IKeyOrder for the given IPredicate.
int	index() The integer used to represent the SPOKeyOrder.
boolean	isPrimaryIndex() Return true if this is the primary index for the relation.
static Iterator<SPOKeyOrder>	quadStoreKeyOrderIterator() Return an iterator which visits the quad store indices (SPOC, POCS, OCSP, CSPO, PCSO, SOPC ).
static Iterator<SPOKeyOrder>	spocOnlyKeyOrderIterator() Return an iterator which visits only SPOC.
static Iterator<SPOKeyOrder>	spoOnlyKeyOrderIterator() Return an iterator which visits only SPO.
String	toString() Return getIndexName()'s value.
static Iterator<SPOKeyOrder>	tripleStoreKeyOrderIterator() Return an iterator which visits the triple store indices (SPO, POS, OSP).
static SPOKeyOrder	valueOf(int index) Returns the singleton corresponding to the index.

Methods inherited from class com.bigdata.striterator.AbstractKeyOrder

getKey

Methods inherited from class java.lang.Object

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

Field Detail

_SPO

public static final transient int _SPO

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Constant Field Values

_OSP

public static final transient int _OSP

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Constant Field Values

_POS

public static final transient int _POS

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Constant Field Values

_SPOC

public static final transient int _SPOC

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Constant Field Values

_POCS

public static final transient int _POCS

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Constant Field Values

_OCSP

public static final transient int _OCSP

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Constant Field Values

_CSPO

public static final transient int _CSPO

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Constant Field Values

_PCSO

public static final transient int _PCSO

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Constant Field Values

_SOPC

public static final transient int _SOPC

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Constant Field Values

FIRST_TRIPLE_INDEX

public static final transient int FIRST_TRIPLE_INDEX

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Constant Field Values

LAST_TRIPLE_INDEX

public static final transient int LAST_TRIPLE_INDEX

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Constant Field Values

FIRST_QUAD_INDEX

public static final transient int FIRST_QUAD_INDEX

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Constant Field Values

LAST_QUAD_INDEX

public static final transient int LAST_QUAD_INDEX

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Constant Field Values

MAX_INDEX_COUNT

public static final transient int MAX_INDEX_COUNT

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Constant Field Values

SPO

public static final transient SPOKeyOrder SPO

POS

public static final transient SPOKeyOrder POS

OSP

public static final transient SPOKeyOrder OSP

SPOC

public static final transient SPOKeyOrder SPOC

POCS

public static final transient SPOKeyOrder POCS

OCSP

public static final transient SPOKeyOrder OCSP

CSPO

public static final transient SPOKeyOrder CSPO

PCSO

public static final transient SPOKeyOrder PCSO

SOPC

public static final transient SPOKeyOrder SOPC

S

public static final transient int S

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Constant Field Values

P

public static final transient int P

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Constant Field Values

O

public static final transient int O

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Constant Field Values

C

public static final transient int C

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Constant Field Values

Method Detail

isPrimaryIndex

public final boolean isPrimaryIndex()

Return true if this is the primary index for the relation.

Returns:

true for SPO or SPOC. Those are the natural orders corresponding to the primary index for a triple store (SPO) and a quad store (SPOC) respectively.

valueOf

public static SPOKeyOrder valueOf(int index)

Returns the singleton corresponding to the index.

Parameters:

index - The index.

Returns:

The singleton SPOKeyOrder having that index.

Throws:

IllegalArgumentException - if the index is not valid.

fromString

public static SPOKeyOrder fromString(String name)

Covert a name of an SPOKeyOrder into an SPOKeyOrder.

Parameters:

name - The name.

Returns:

The SPOKeyOrder.

Throws:

IllegalArgumentException - if name is not a known SPOKeyOrder.

getIndexName

public final String getIndexName()

The base name for the index.

Specified by:

getIndexName in interface IKeyOrder<ISPO>

toString

public String toString()

Return getIndexName()'s value.

Overrides:

toString in class Object

getKeyArity

public final int getKeyArity()

Return either 3 or 4 depending on the #of components in the key for this natural key ordering.

Specified by:

getKeyArity in interface IKeyOrder<ISPO>

getKeyOrder

public final int getKeyOrder(int keyPos)

Return the index of the slot in the ISPO tuple which appears at the specified position in the key.

Specified by:

getKeyOrder in interface IKeyOrder<ISPO>

Parameters:

keyPos - The index into the key that is being generated.

Returns:

The index of the slot in the ISPO.

getPositionInIndex

public final int getPositionInIndex(int spoIdentifier)

Returns the position of the given spoIdentifier in the index. For instance, if the index is POS and spoIdentfier==0 (representing the subject, then 2 is returned (since the subject shows up in index position 2 in POS).

Parameters:

spoIdentifier - identifier, either being 0=subject, 1=predicate, 2=object, or 3=context

Returns:

the position in the key or -1 if not matchable (e.g., if we're in triples mode and request the index for c)

index

public final int index()

The integer used to represent the SPOKeyOrder. For a triple store, this is one of the constants: _SPO, POS, or OSP. For a quad store, this is one of the constants _SPOC, _POCS, _OCSP, _CSPO, _PCSO, _SOPC.

getComparator

public final Comparator<ISPO> getComparator()

Return the comparator that places ISPOs into the natural order for the associated index.

Specified by:

getComparator in interface IKeyOrder<ISPO>

getFromKey

public byte[] getFromKey(IKeyBuilder keyBuilder,
                IPredicate<ISPO> predicate)

Return the inclusive lower bound which would be used for a query against this IKeyOrder for the given IPredicate. TODO I think that we should just rely on the correct attachment of the range constraint filters to the SPs (and the propagation of the constraints to the IPredicates) rather than doing dynamic attachment here. Static analysis can determine when the variable will become bound, whether in the scope of a required join group or an optional join group. (In the case of the optional join group, the joins in the group are still required joins, it is just that the solutions outside of the group will not have a binding for the variable unless it became bound within the optional group. However, this does not change how we attach the range constraints to the SPs since a range constraint which is lifted onto the AP can only be applied when the variable would become bound by that AP. If the variable is already bound, it is of no consequence. The only wrinkle would be when one optional group MIGHT have already bound a variable and then another optional group which could also bind the same variable could observe either a bound variable or an unbound variable. The FILTER would have to be in place in both optional groups and the range constraint would be lifted onto the access path in both groups.)

Specified by:

getFromKey in interface IKeyOrder<ISPO>

Overrides:

getFromKey in class AbstractKeyOrder<ISPO>

Parameters:

keyBuilder - The object which will be used to construct the key.

predicate - A predicate describing bound and unbound fields for the key.

Returns:

The key corresponding to the inclusive lower bound for a query against that IPredicate.

See Also:

(lift range constraints onto AP).

getToKey

public byte[] getToKey(IKeyBuilder keyBuilder,
              IPredicate<ISPO> predicate)

Return the exclusive upper bound which would be used for a query against this IKeyOrder for the given IPredicate. TODO See my notes on getFromKey(). The issue is exactly the same for the toKey and fromKey. TODO Each GT(E)/LT(E) constraint should be broken down into a separate filter so we can apply one even when the other might depend on a variable which is not yet bound.

Specified by:

getToKey in interface IKeyOrder<ISPO>

Overrides:

getToKey in class AbstractKeyOrder<ISPO>

Parameters:

keyBuilder - The object which will be used to construct the key.

predicate - A predicate describing bound and unbound fields for the key.

Returns:

The key corresponding to the exclusive upper bound for a query against that IPredicate.

See Also:

(lift range constraints onto AP).

appendKeyComponent

protected void appendKeyComponent(IKeyBuilder keyBuilder,
                      int index,
                      Object keyComponent)

Description copied from class: AbstractKeyOrder

Encodes an value into the key. This implementation uses the default behavior of IKeyBuilder. If you need to specialize how a value gets encoded into the key then you can override this method.

Overrides:

appendKeyComponent in class AbstractKeyOrder<ISPO>

encodeKey

public final byte[] encodeKey(IKeyBuilder keyBuilder,
               ISPO spo)

Forms the key for a given index order (the SPOTupleSerializer delegates its behavior to this method).

Note: The IKeyBuilder is IKeyBuilder.reset() by this method.

Parameters:

keyBuilder - The key builder.

spo - The ISPO.

Returns:

The encoded key.

See Also:

appendKey(IKeyBuilder, ISPO)

appendKey

public final IKeyBuilder appendKey(IKeyBuilder keyBuilder,
                    ISPO spo)

Appends the key for a given index order into the IKeyBuilder.

Note: The IKeyBuilder is NOT IKeyBuilder.reset() by this method.

Parameters:

keyBuilder - The key builder - this is NOT reset().

spo - The ISPO.

Returns:

The IKeyBuilder.

See Also:

appendKey(IKeyBuilder, ISPO)

decodeKey

public final SPO decodeKey(byte[] key)

Decode the key into an SPO. The StatementEnum and the optional SID will not be decoded, since it is carried in the B+Tree value. However, if the SPOKeyOrder is a quad order then the SPO.c() will be bound.

Parameters:

key - The key.

Returns:

The decoded key.

decodeKey

public final SPO decodeKey(byte[] key,
            int offset)

Decode the key into an SPO. The StatementEnum and the optional SID will not be decoded, since it is carried in the B+Tree value. However, if the SPOKeyOrder is a quad order then the SPO.c() will be bound.

Parameters:

key - The key.

offset - The offset into the key.

Returns:

The decoded key.

getKeyOrder

public static SPOKeyOrder getKeyOrder(IPredicate<ISPO> predicate,
                      int keyArity)

Return the SPOKeyOrder for the given predicate.

Parameters:

predicate - The predicate.

Returns:

The SPOKeyOrder

See Also:

Choosing the index for testing fully bound access paths based on index locality

tripleStoreKeyOrderIterator

public static Iterator<SPOKeyOrder> tripleStoreKeyOrderIterator()

Return an iterator which visits the triple store indices (SPO, POS, OSP).

quadStoreKeyOrderIterator

public static Iterator<SPOKeyOrder> quadStoreKeyOrderIterator()

Return an iterator which visits the quad store indices (SPOC, POCS, OCSP, CSPO, PCSO, SOPC ).

spoOnlyKeyOrderIterator

public static Iterator<SPOKeyOrder> spoOnlyKeyOrderIterator()

Return an iterator which visits only SPO.

spocOnlyKeyOrderIterator

public static Iterator<SPOKeyOrder> spocOnlyKeyOrderIterator()

Return an iterator which visits only SPOC.