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[Bigdata-commit] SF.net SVN: bigdata:[4103] branches/QUADS_QUERY_BRANCH/bigdata-sails/src/ java/com/bigdata/rdf/sail
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From: <tho...@us...> - 2011-01-15 21:23:29
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Revision: 4103
http://bigdata.svn.sourceforge.net/bigdata/?rev=4103&view=rev
Author: thompsonbry
Date: 2011-01-15 21:23:23 +0000 (Sat, 15 Jan 2011)
Log Message:
-----------
Javadoc on QueryHints.
Bugfix to the BigdataEvaluationStrategyImpl to address problems where a smaller buffer backing the BigdataBindingSetResolverator could result in a deadlock during query (e.g., LUBM U50 Q8).
Modified Paths:
--------------
branches/QUADS_QUERY_BRANCH/bigdata-sails/src/java/com/bigdata/rdf/sail/BigdataEvaluationStrategyImpl.java
branches/QUADS_QUERY_BRANCH/bigdata-sails/src/java/com/bigdata/rdf/sail/QueryHints.java
Modified: branches/QUADS_QUERY_BRANCH/bigdata-sails/src/java/com/bigdata/rdf/sail/BigdataEvaluationStrategyImpl.java
===================================================================
--- branches/QUADS_QUERY_BRANCH/bigdata-sails/src/java/com/bigdata/rdf/sail/BigdataEvaluationStrategyImpl.java 2011-01-15 14:59:52 UTC (rev 4102)
+++ branches/QUADS_QUERY_BRANCH/bigdata-sails/src/java/com/bigdata/rdf/sail/BigdataEvaluationStrategyImpl.java 2011-01-15 21:23:23 UTC (rev 4103)
@@ -1710,106 +1710,167 @@
// startId, -1/* partitionId */,
// newBindingSetIterator(new HashBindingSet())));
- final IRunningQuery runningQuery = queryEngine.eval(query);
+ IRunningQuery runningQuery = null;
+ try {
+
+ // Submit query for evaluation.
+ runningQuery = queryEngine.eval(query);
+
+ // Iterator draining the query results.
+ final IAsynchronousIterator<IBindingSet[]> it1 =
+ runningQuery.iterator();
+
+ // De-chunk the IBindingSet[] visited by that iterator.
+ final IChunkedOrderedIterator<IBindingSet> it2 =
+ new ChunkedWrappedIterator<IBindingSet>(
+ new Dechunkerator<IBindingSet>(it1));
- final IAsynchronousIterator<IBindingSet[]> it1 =
- runningQuery.iterator();
-
-// final IChunkedOrderedIterator<IBindingSet> it2 =
-// new ChunkedArraysIterator<IBindingSet>(it1);
- final IChunkedOrderedIterator<IBindingSet> it2 = new ChunkedWrappedIterator<IBindingSet>(
- new Dechunkerator<IBindingSet>(it1));
-
- CloseableIteration<BindingSet, QueryEvaluationException> result =
- new Bigdata2Sesame2BindingSetIterator<QueryEvaluationException>(
- new BigdataBindingSetResolverator(database, it2).start(database
- .getExecutorService()));
+ // Materialize IVs as RDF Values.
+ CloseableIteration<BindingSet, QueryEvaluationException> result =
+ // Monitor IRunningQuery and cancel if Sesame iterator is closed.
+ new RunningQueryCloseableIteration<BindingSet, QueryEvaluationException>(runningQuery,
+ // Convert bigdata binding sets to Sesame binding sets.
+ new Bigdata2Sesame2BindingSetIterator<QueryEvaluationException>(
+ // Materialize IVs as RDF Values.
+ new BigdataBindingSetResolverator(database, it2).start(
+ database.getExecutorService())));
+
+// No - will deadlock if buffer fills up
+// // Wait for the Future (checks for errors).
+// runningQuery.get();
+
+ // use the basic filter iterator for remaining filters
+ if (step instanceof ProxyRuleWithSesameFilters) {
+ Collection<Filter> filters =
+ ((ProxyRuleWithSesameFilters) step).getSesameFilters();
+ if (log.isInfoEnabled() && filters.size() > 0) {
+ log.info("could not translate " + filters.size()
+ + " filters into native constraints:");
+ }
+ for (Filter filter : filters) {
+ if (log.isInfoEnabled())
+ log.info("\n" + filter.getCondition());
+ result = new FilterIterator(filter, result, this);
+ }
+ }
+// // use the basic filter iterator for remaining filters
+// if (sesameFilters != null) {
+// for (Filter f : sesameFilters) {
+// if (log.isDebugEnabled()) {
+// log.debug("attaching sesame filter: " + f);
+// }
+// result = new FilterIterator(f, result, this);
+// }
+// }
- /*
- * FIXME This will deadlock in the buffer fills - see
- * BigdataEvaluationStrategyImpl3 which contains a new code pattern for
- * this.
- */
- try {
- // Wait for the Future (checks for errors).
- runningQuery.get();
- } catch (Exception ex) {
- throw new QueryEvaluationException(ex);
- }
-
-// final boolean backchain = //
-// tripleSource.getDatabase().getAxioms().isRdfSchema()
-// && tripleSource.includeInferred
-// && tripleSource.conn.isQueryTimeExpander();
+ return result;
+
+ } catch (Throwable t) {
+ if (runningQuery != null)
+ runningQuery.cancel(true/* mayInterruptIfRunning */);
+ throw new QueryEvaluationException(t);
+ }
+
+// final IRunningQuery runningQuery = queryEngine.eval(query);
+//
+// final IAsynchronousIterator<IBindingSet[]> it1 =
+// runningQuery.iterator();
//
-// if (log.isDebugEnabled()) {
-// log.debug("Running tupleExpr as native rule:\n" + step);
-// log.debug("backchain: " + backchain);
-// }
+//// final IChunkedOrderedIterator<IBindingSet> it2 =
+//// new ChunkedArraysIterator<IBindingSet>(it1);
+// final IChunkedOrderedIterator<IBindingSet> it2 = new ChunkedWrappedIterator<IBindingSet>(
+// new Dechunkerator<IBindingSet>(it1));
//
-// // run the query as a native rule.
-// final IChunkedOrderedIterator<ISolution> itr1;
+// CloseableIteration<BindingSet, QueryEvaluationException> result =
+// new Bigdata2Sesame2BindingSetIterator<QueryEvaluationException>(
+// new BigdataBindingSetResolverator(database, it2).start(database
+// .getExecutorService()));
+//
+// /*
+// * FIXME This will deadlock in the buffer fills - see
+// * BigdataEvaluationStrategyImpl3 which contains a new code pattern for
+// * this.
+// */
// try {
-// final IEvaluationPlanFactory planFactory =
-// DefaultEvaluationPlanFactory2.INSTANCE;
-//
-// /*
-// * alternative evaluation orders for LUBM Q9 (default is 1 4, 2, 3,
-// * 0, 5). All three evaluation orders are roughly as good as one
-// * another. Note that tail[2] (z rdf:type ...) is entailed by the
-// * ontology and could be dropped from evaluation.
-// */
-// // final IEvaluationPlanFactory planFactory = new
-// // FixedEvaluationPlanFactory(
-// // // new int[] { 1, 4, 3, 0, 5, 2 } good
-// // // new int[] { 1, 3, 0, 4, 5, 2 } good
-// // );
-//
-// final IJoinNexusFactory joinNexusFactory = database
-// .newJoinNexusFactory(RuleContextEnum.HighLevelQuery,
-// ActionEnum.Query, IJoinNexus.BINDINGS,
-// null, // filter
-// false, // justify
-// backchain, //
-// planFactory, //
-// queryHints
-// );
-//
-// final IJoinNexus joinNexus = joinNexusFactory.newInstance(database
-// .getIndexManager());
-// itr1 = joinNexus.runQuery(step);
-//
+// // Wait for the Future (checks for errors).
+// runningQuery.get();
// } catch (Exception ex) {
// throw new QueryEvaluationException(ex);
// }
//
-// /*
-// * Efficiently resolve term identifiers in Bigdata ISolutions to RDF
-// * Values in Sesame 2 BindingSets and align the resulting iterator with
-// * the Sesame 2 API.
-// */
-// CloseableIteration<BindingSet, QueryEvaluationException> result =
-// new Bigdata2Sesame2BindingSetIterator<QueryEvaluationException>(
-// new BigdataSolutionResolverator(database, itr1).start(database
-// .getExecutorService()));
+//// final boolean backchain = //
+//// tripleSource.getDatabase().getAxioms().isRdfSchema()
+//// && tripleSource.includeInferred
+//// && tripleSource.conn.isQueryTimeExpander();
+////
+//// if (log.isDebugEnabled()) {
+//// log.debug("Running tupleExpr as native rule:\n" + step);
+//// log.debug("backchain: " + backchain);
+//// }
+////
+//// // run the query as a native rule.
+//// final IChunkedOrderedIterator<ISolution> itr1;
+//// try {
+//// final IEvaluationPlanFactory planFactory =
+//// DefaultEvaluationPlanFactory2.INSTANCE;
+////
+//// /*
+//// * alternative evaluation orders for LUBM Q9 (default is 1 4, 2, 3,
+//// * 0, 5). All three evaluation orders are roughly as good as one
+//// * another. Note that tail[2] (z rdf:type ...) is entailed by the
+//// * ontology and could be dropped from evaluation.
+//// */
+//// // final IEvaluationPlanFactory planFactory = new
+//// // FixedEvaluationPlanFactory(
+//// // // new int[] { 1, 4, 3, 0, 5, 2 } good
+//// // // new int[] { 1, 3, 0, 4, 5, 2 } good
+//// // );
+////
+//// final IJoinNexusFactory joinNexusFactory = database
+//// .newJoinNexusFactory(RuleContextEnum.HighLevelQuery,
+//// ActionEnum.Query, IJoinNexus.BINDINGS,
+//// null, // filter
+//// false, // justify
+//// backchain, //
+//// planFactory, //
+//// queryHints
+//// );
+////
+//// final IJoinNexus joinNexus = joinNexusFactory.newInstance(database
+//// .getIndexManager());
+//// itr1 = joinNexus.runQuery(step);
+////
+//// } catch (Exception ex) {
+//// throw new QueryEvaluationException(ex);
+//// }
+////
+//// /*
+//// * Efficiently resolve term identifiers in Bigdata ISolutions to RDF
+//// * Values in Sesame 2 BindingSets and align the resulting iterator with
+//// * the Sesame 2 API.
+//// */
+//// CloseableIteration<BindingSet, QueryEvaluationException> result =
+//// new Bigdata2Sesame2BindingSetIterator<QueryEvaluationException>(
+//// new BigdataSolutionResolverator(database, itr1).start(database
+//// .getExecutorService()));
+//
+// // use the basic filter iterator for remaining filters
+// if (step instanceof ProxyRuleWithSesameFilters) {
+// Collection<Filter> filters =
+// ((ProxyRuleWithSesameFilters) step).getSesameFilters();
+// if (log.isInfoEnabled() && filters.size() > 0) {
+// log.info("could not translate " + filters.size()
+// + " filters into native constraints:");
+// }
+// for (Filter filter : filters) {
+// if (log.isInfoEnabled())
+// log.info("\n" + filter.getCondition());
+// result = new FilterIterator(filter, result, this);
+// }
+// }
+//
+// return result;
- // use the basic filter iterator for remaining filters
- if (step instanceof ProxyRuleWithSesameFilters) {
- Collection<Filter> filters =
- ((ProxyRuleWithSesameFilters) step).getSesameFilters();
- if (log.isInfoEnabled() && filters.size() > 0) {
- log.info("could not translate " + filters.size()
- + " filters into native constraints:");
- }
- for (Filter filter : filters) {
- if (log.isInfoEnabled())
- log.info("\n" + filter.getCondition());
- result = new FilterIterator(filter, result, this);
- }
- }
-
- return result;
-
}
// /**
Modified: branches/QUADS_QUERY_BRANCH/bigdata-sails/src/java/com/bigdata/rdf/sail/QueryHints.java
===================================================================
--- branches/QUADS_QUERY_BRANCH/bigdata-sails/src/java/com/bigdata/rdf/sail/QueryHints.java 2011-01-15 14:59:52 UTC (rev 4102)
+++ branches/QUADS_QUERY_BRANCH/bigdata-sails/src/java/com/bigdata/rdf/sail/QueryHints.java 2011-01-15 21:23:23 UTC (rev 4103)
@@ -56,11 +56,22 @@
*/
String NAMESPACE = "BIGDATA_QUERY_HINTS";
- /**
- * Specify the query optimizer.
- *
- * @see QueryOptimizerEnum
- */
+ /**
+ * Specify the query optimizer. For example, you can disable the query
+ * optimizer using
+ *
+ * <pre>
+ * PREFIX BIGDATA_QUERY_HINTS: <http://www.bigdata.com/queryHints#com.bigdata.rdf.sail.QueryHints.optimizer=None>
+ * </pre>
+ *
+ * Disabling the query optimizer can be useful if you have a query for which
+ * the static query optimizer is producing a inefficient join ordering. With
+ * the query optimizer disabled for that query, the joins will be run in the
+ * order given. This makes it possible for you to decide on the right join
+ * ordering for that query.
+ *
+ * @see QueryOptimizerEnum
+ */
String OPTIMIZER = QueryHints.class.getName() + ".optimizer";
}
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