Github user kchilton2 commented on a diff in the pull request:
https://github.com/apache/incubator-rya/pull/172#discussion_r160792306
--- Diff:
extras/rya.indexing.pcj/src/main/java/org/apache/rya/indexing/pcj/storage/mongo/MongoPcjDocuments.java
---
@@ -0,0 +1,451 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements. See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership. The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License. You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied. See the License for the
+ * specific language governing permissions and limitations
+ * under the License.
+ */
+package org.apache.rya.indexing.pcj.storage.mongo;
+
+import static com.google.common.base.Preconditions.checkNotNull;
+import static java.util.Objects.requireNonNull;
+
+import java.util.ArrayList;
+import java.util.Collection;
+import java.util.HashSet;
+import java.util.Iterator;
+import java.util.List;
+import java.util.Set;
+
+import org.apache.accumulo.core.security.Authorizations;
+import org.apache.rya.api.domain.RyaType;
+import org.apache.rya.api.model.VisibilityBindingSet;
+import org.apache.rya.api.resolver.RdfToRyaConversions;
+import org.apache.rya.api.resolver.RyaToRdfConversions;
+import org.apache.rya.api.utils.CloseableIterator;
+import org.apache.rya.indexing.pcj.storage.PcjMetadata;
+import
org.apache.rya.indexing.pcj.storage.PrecomputedJoinStorage.PCJStorageException;
+import org.apache.rya.indexing.pcj.storage.accumulo.PcjVarOrderFactory;
+import org.apache.rya.indexing.pcj.storage.accumulo.ShiftVarOrderFactory;
+import org.apache.rya.indexing.pcj.storage.accumulo.VariableOrder;
+import org.bson.Document;
+import org.bson.conversions.Bson;
+import org.openrdf.model.URI;
+import org.openrdf.model.Value;
+import org.openrdf.model.impl.URIImpl;
+import org.openrdf.query.BindingSet;
+import org.openrdf.query.MalformedQueryException;
+import org.openrdf.query.QueryEvaluationException;
+import org.openrdf.query.QueryLanguage;
+import org.openrdf.query.TupleQuery;
+import org.openrdf.query.TupleQueryResult;
+import org.openrdf.query.impl.MapBindingSet;
+import org.openrdf.repository.RepositoryConnection;
+import org.openrdf.repository.RepositoryException;
+
+import com.mongodb.MongoClient;
+import com.mongodb.client.FindIterable;
+import com.mongodb.client.MongoCollection;
+import com.mongodb.util.JSON;
+
+/**
+ * Creates and modifies PCJs in MongoDB. PCJ's are stored as follows:
+ *
+ * <pre>
+ * <code>
+ * ----- PCJ Metadata Doc -----
+ * {
+ * _id: [pcj_name]_METADATA,
+ * sparql: [sparql query to match results],
+ * varOrders: [varOrder1, VarOrder2, ..., VarOrdern]
+ * cardinality: [number of results]
+ * }
+ *
+ * ----- PCJ Results Doc -----
--- End diff --
This has an _id field, right? Does it use a random mongo ID right now?
---
