com.bigdata.rdf.internal.encoder

Class IVBindingSetEncoderWithIVCache

java.lang.Object

com.bigdata.rdf.internal.encoder.IVBindingSetEncoder

com.bigdata.rdf.internal.encoder.IVBindingSetEncoderWithIVCache

All Implemented Interfaces:

IBindingSetDecoder, IBindingSetEncoder

Deprecated.

@Deprecated
public class IVBindingSetEncoderWithIVCache
extends IVBindingSetEncoder

A concrete implementation using scalable BTrees to store the mapping from an IV to the cached RDF Value. This approach is useful when you will be encoding a LOT of data and you need to get the cached RDF Value objects off of the JVM heap.

Note: Two different BTree instances are used. One for TermIds and another for BlobIVs. These indices use exactly the same schema as the ID2TERM and BLOBS indices.

Version:

$Id$ This class is out of use. As part of https://jira.blazegraph.com/browse/BLZG-1899, we carried out some experiments illustrating that caching the IVs (i.e., preserving them in HTree hash joins) is far slower than just re-materializing them. We decided to retire the class and, instead, do remove variables from the doneSet within the AST2BOpUtility update process whenever we set up an analytic hash join.

Author:

Bryan Thompson

Field Summary

Fields

Modifier and Type	Field and Description
protected LinkedHashSet<IVariable<?>>	ivCacheSchema Deprecated. The set of variables for which materialized IVs have been observed.

Fields inherited from class com.bigdata.rdf.internal.encoder.IVBindingSetEncoder

filter, vf

Constructor Summary

Constructors

Constructor and Description
IVBindingSetEncoderWithIVCache(IRawStore store, boolean filter, BOp op) Deprecated.

Method Summary

Methods

Modifier and Type	Method and Description
void	flush() Deprecated. Flush any updates.
boolean	isValueCache() Deprecated. Return true iff the IVCache associations are preserved by the encoder.
void	release() Deprecated. Release the state associated with the IVBindingSetEncoder.
void	resolveCachedValues(IBindingSet bset) Deprecated. Resolve any IVs in the solution for which there are cached BigdataValues to those values.
void	saveSolutionSet() Deprecated. Checkpoint the BTree instance(s) used to buffer the cached IV to RDF Value mappings and then re-load the them in a read-only mode from their checkpoint(s).
String	toString() Deprecated.

Methods inherited from class com.bigdata.rdf.internal.encoder.IVBindingSetEncoder

decodeSolution, encodeSolution, encodeSolution

Methods inherited from class java.lang.Object

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

Field Detail

ivCacheSchema

protected final LinkedHashSet<IVariable<?>> ivCacheSchema

Deprecated.

The set of variables for which materialized IVs have been observed.

Constructor Detail

IVBindingSetEncoderWithIVCache

public IVBindingSetEncoderWithIVCache(IRawStore store,
                              boolean filter,
                              BOp op)

Deprecated.

Parameters:

store - The backing IRawStore for the IV to BigdataValue cache.

filter - true iff this is in support of a DISTINCT filter.

Note: we do not maintain the ivCacheSchema for a DISTINCT filter since the original solutions flow through the filter.

op - The operator whose annotations are used to parameterize the creation of the backing indices for the IV to BigdataValue cache.

Method Detail

toString

public String toString()

Deprecated.

Overrides:

toString in class Object

isValueCache

public boolean isValueCache()

Deprecated.

Return true iff the IVCache associations are preserved by the encoder.

This implementation does not maintain the IVCache associations.

This maintains the IVCache associations UNLESS filter:=true was specified to the constructor.

Specified by:

isValueCache in interface IBindingSetDecoder

Specified by:

isValueCache in interface IBindingSetEncoder

Overrides:

isValueCache in class IVBindingSetEncoder

saveSolutionSet

public void saveSolutionSet()

Deprecated.

Checkpoint the BTree instance(s) used to buffer the cached IV to RDF Value mappings and then re-load the them in a read-only mode from their checkpoint(s). This exposes a view of the BTree instance(s) which is safe for concurrent readers.

release

public void release()

Deprecated.

Description copied from interface: IBindingSetEncoder

Release the state associated with the IVBindingSetEncoder.

Specified by:

release in interface IBindingSetDecoder

Specified by:

release in interface IBindingSetEncoder

Overrides:

release in class IVBindingSetEncoder

flush

public void flush()

Deprecated.

Flush any updates. This allows for vectored operations when updating the IVCache associations.

Vectored update of the internal ivCache.

Specified by:

flush in interface IBindingSetEncoder

Overrides:

flush in class IVBindingSetEncoder

resolveCachedValues

public void resolveCachedValues(IBindingSet bset)

Deprecated.

Resolve any IVs in the solution for which there are cached BigdataValues to those values. This method may be used to resolve IVCache associations for IBindingSets NOT produced by IBindingSetDecoder.decodeSolution(byte[], int, int, boolean). For example, when joining a decoded solution with another solution, the resolution step may be deferred until we know whether or not the join was successful.

Note: This implementation is a NOP as the IVCache association is NOT maintained by this class. TODO If we vectored this operation it would substantially reduce its costs. We would have to collect up a bunch of solutions which needed resolution, then collect up the IVs which do not have cached values for variables which might have values in the ivCache. We would then sort the IVs and do a vectored resolution against the ivCache. Finally, the solutions could be output in a chunk with their resolved Values.

If the operator is not vectored, then we should just fold it into #decodeSolution(byte[], int, int).

Specified by:

resolveCachedValues in interface IBindingSetDecoder

Overrides:

resolveCachedValues in class IVBindingSetEncoder

Parameters:

bset - A solution having IVs which need to be reunited with their cached BigdataValues.