/**
Copyright (C) SYSTAP, LLC DBA Blazegraph 2006-2016. All rights reserved.
Contact:
SYSTAP, LLC DBA Blazegraph
2501 Calvert ST NW #106
Washington, DC 20008
licenses@blazegraph.com
This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; version 2 of the License.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program; if not, write to the Free Software
Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*/
package com.bigdata.bop.joinGraph.rto;
import com.bigdata.bop.IBindingSet;
/**
* A sample produced by a cutoff join.
*/
public class EdgeSample extends SampleBase {
// private static final transient Logger log = Logger
// .getLogger(EdgeSample.class);
/**
* The source sample used to compute the cutoff join.
*/
public final SampleBase sourceSample;
/**
* The #of binding sets out of the source sample vertex sample which were
* consumed.
*/
public final int inputCount;
/**
* The #of tuples read from the access path when processing the cutoff join.
*/
public final long tuplesRead;
/**
* The #of binding sets generated before the join was cutoff.
* <p>
* Note: If the outputCount is zero then this is a good indicator that there
* is an error in the query such that the join will not select anything.
* This is not 100%, merely indicative.
*/
public final long outputCount;
/**
* The adjusted cardinality estimate for the cutoff join (this is
* {@link #outputCount} as adjusted for a variety of edge conditions).
*/
public final long adjCard;
/**
* The ratio of the #of input samples consumed to the #of output samples
* generated (the join hit ratio or scale factor).
*/
public final double f;
/**
* The sum of the fast range count for each access path tested.
* <p>
* Note: We use pipeline joins to sample cutoff joins so there will be one
* access path read for each solution in. However, a hash join could be used
* when the operator is fully executed. The hash join will have one access
* path on which we read for all input solutions and the range count of the
* access path will be larger since the access path will be less
* constrained.
*/
public final long sumRangeCount;
/**
* Estimated tuples read if the operator were fully executed. This is in
* contrast to {@link SampleBase#estCard}, which is the estimated output
* cardinality if the operator were fully executed.
*
* TODO The actual IOs depend on the join type (hash join versus pipeline
* join) and whether or not the file has index order (segment versus
* journal). A hash join will read once on the AP. A pipeline join will read
* once per input solution. A key-range read on a segment uses multi-block
* IO while a key-range read on a journal uses random IO. Also, remote
* access path reads are more expensive than sharded or hash partitioned
* access path reads in scale-out.
*/
public final long estRead;
/**
* Create an object which encapsulates a sample of an edge.
*
* @param sourceSample
* The input sample.
* @param limit
* The limit used to sample the edge (this is the limit on the
* #of solutions generated by the cutoff join used when this
* sample was taken).
* @param inputCount
* The #of binding sets out of the source sample vertex sample
* which were consumed.
* @param tuplesRead
* The #of tuples read from the access path when processing the
* cutoff join.
* @param outputCount
* The #of binding sets generated before the join was cutoff.
* @param adjustedCard
* The adjusted cardinality estimate for the cutoff join (this is
* <i>outputCount</i> as adjusted for a variety of edge
* conditions).
*/
public EdgeSample(final SampleBase sourceSample,//
final int inputCount, //
final long tuplesRead,//
final long sumRangeCount,//
final long outputCount,//
final long adjustedCard,//
final double f, //
// args to SampleBase
final long estCard,//
final long estRead,//
final int limit,//
final EstimateEnum estimateEnum,//
final IBindingSet[] sample//
) {
super(estCard, limit, estimateEnum, sample);
if (sourceSample == null)
throw new IllegalArgumentException();
this.sourceSample = sourceSample;
this.inputCount = inputCount;
this.tuplesRead = tuplesRead;
this.sumRangeCount = sumRangeCount;
this.outputCount = outputCount;
this.adjCard = adjustedCard;
this.f = f;
this.estRead = estRead;
}
@Override
protected void toString(final StringBuilder sb) {
sb.append(", sourceEstCard=" + sourceSample.estCard);
sb.append(", sourceEstimateEnum=" + sourceSample.estimateEnum);
sb.append(", inputCount=" + inputCount);
sb.append(", tuplesRead=" + tuplesRead);
sb.append(", sumRangeCount=" + sumRangeCount);
sb.append(", outputCount=" + outputCount);
sb.append(", adjustedCard=" + adjCard);
sb.append(", f=" + f);
sb.append(", estRead=" + estRead);
}
}