diff --git a/java/com/google/gerrit/acceptance/GerritServer.java b/java/com/google/gerrit/acceptance/GerritServer.java
index 6f54e84bf9..25315b6c96 100644
--- a/java/com/google/gerrit/acceptance/GerritServer.java
+++ b/java/com/google/gerrit/acceptance/GerritServer.java
@@ -39,6 +39,7 @@ import com.google.gerrit.server.config.GerritRuntime;
 import com.google.gerrit.server.config.GerritServerConfig;
 import com.google.gerrit.server.config.SitePath;
 import com.google.gerrit.server.git.receive.AsyncReceiveCommits;
+import com.google.gerrit.server.schema.JdbcAccountPatchReviewStore;
 import com.google.gerrit.server.ssh.NoSshModule;
 import com.google.gerrit.server.util.SocketUtil;
 import com.google.gerrit.server.util.SystemLog;
@@ -388,6 +389,8 @@ public class GerritServer implements AutoCloseable {
     cfg.setBoolean("sshd", null, "requestLog", false);
     cfg.setBoolean("index", "lucene", "testInmemory", true);
     cfg.setString("gitweb", null, "cgi", "");
+    cfg.setString(
+        "accountPatchReviewDb", null, "url", JdbcAccountPatchReviewStore.TEST_IN_MEMORY_URL);
     daemon.setEnableHttpd(desc.httpd());
     daemon.setLuceneModule(LuceneIndexModule.singleVersionAllLatest(0, isSlave(baseConfig)));
     daemon.setDatabaseForTesting(
diff --git a/java/com/google/gerrit/elasticsearch/AbstractElasticIndex.java b/java/com/google/gerrit/elasticsearch/AbstractElasticIndex.java
index 0379423ab1..ef4ef40ab3 100644
--- a/java/com/google/gerrit/elasticsearch/AbstractElasticIndex.java
+++ b/java/com/google/gerrit/elasticsearch/AbstractElasticIndex.java
@@ -20,6 +20,7 @@ import static com.google.gson.FieldNamingPolicy.LOWER_CASE_WITH_UNDERSCORES;
 import static java.nio.charset.StandardCharsets.UTF_8;
 
 import com.google.common.collect.ArrayListMultimap;
+import com.google.common.collect.ImmutableList;
 import com.google.common.collect.ImmutableMap;
 import com.google.common.collect.ListMultimap;
 import com.google.common.collect.Lists;
@@ -38,8 +39,10 @@ import com.google.gerrit.index.QueryOptions;
 import com.google.gerrit.index.Schema;
 import com.google.gerrit.index.query.DataSource;
 import com.google.gerrit.index.query.FieldBundle;
+import com.google.gerrit.index.query.ListResultSet;
 import com.google.gerrit.index.query.Predicate;
 import com.google.gerrit.index.query.QueryParseException;
+import com.google.gerrit.index.query.ResultSet;
 import com.google.gerrit.proto.Protos;
 import com.google.gerrit.reviewdb.converter.ProtoConverter;
 import com.google.gerrit.server.config.SitePaths;
@@ -51,7 +54,6 @@ import com.google.gson.JsonElement;
 import com.google.gson.JsonObject;
 import com.google.gson.JsonParser;
 import com.google.gwtorm.server.OrmException;
-import com.google.gwtorm.server.ResultSet;
 import com.google.protobuf.MessageLite;
 import java.io.IOException;
 import java.io.InputStream;
@@ -62,7 +64,6 @@ import java.net.URLEncoder;
 import java.sql.Timestamp;
 import java.util.Collections;
 import java.util.HashMap;
-import java.util.Iterator;
 import java.util.List;
 import java.util.Map;
 import java.util.Set;
@@ -385,7 +386,6 @@ abstract class AbstractElasticIndex<K, V> implements Index<K, V> {
 
     private <T> ResultSet<T> readImpl(Function<JsonObject, T> mapper) throws OrmException {
       try {
-        List<T> results = Collections.emptyList();
         String uri = getURI(index, SEARCH);
         Response response =
             performRequest(HttpPost.METHOD_NAME, uri, search, Collections.emptyMap());
@@ -396,34 +396,19 @@ abstract class AbstractElasticIndex<K, V> implements Index<K, V> {
               new JsonParser().parse(content).getAsJsonObject().getAsJsonObject("hits");
           if (obj.get("hits") != null) {
             JsonArray json = obj.getAsJsonArray("hits");
-            results = Lists.newArrayListWithCapacity(json.size());
+            ImmutableList.Builder<T> results = ImmutableList.builderWithExpectedSize(json.size());
             for (int i = 0; i < json.size(); i++) {
               T mapperResult = mapper.apply(json.get(i).getAsJsonObject());
               if (mapperResult != null) {
                 results.add(mapperResult);
               }
             }
+            return new ListResultSet<>(results.build());
           }
         } else {
           logger.atSevere().log(statusLine.getReasonPhrase());
         }
-        final List<T> r = Collections.unmodifiableList(results);
-        return new ResultSet<T>() {
-          @Override
-          public Iterator<T> iterator() {
-            return r.iterator();
-          }
-
-          @Override
-          public List<T> toList() {
-            return r;
-          }
-
-          @Override
-          public void close() {
-            // Do nothing.
-          }
-        };
+        return new ListResultSet<>(ImmutableList.of());
       } catch (IOException e) {
         throw new OrmException(e);
       }
diff --git a/java/com/google/gerrit/index/Index.java b/java/com/google/gerrit/index/Index.java
index 2d7e31e182..f60c08fe6f 100644
--- a/java/com/google/gerrit/index/Index.java
+++ b/java/com/google/gerrit/index/Index.java
@@ -14,6 +14,7 @@
 
 package com.google.gerrit.index;
 
+import com.google.common.collect.ImmutableList;
 import com.google.gerrit.index.query.DataSource;
 import com.google.gerrit.index.query.FieldBundle;
 import com.google.gerrit.index.query.IndexPredicate;
@@ -21,7 +22,6 @@ import com.google.gerrit.index.query.Predicate;
 import com.google.gerrit.index.query.QueryParseException;
 import com.google.gwtorm.server.OrmException;
 import java.io.IOException;
-import java.util.List;
 import java.util.Optional;
 
 /**
@@ -95,7 +95,7 @@ public interface Index<K, V> {
    */
   default Optional<V> get(K key, QueryOptions opts) throws IOException {
     opts = opts.withStart(0).withLimit(2);
-    List<V> results;
+    ImmutableList<V> results;
     try {
       results = getSource(keyPredicate(key), opts).read().toList();
     } catch (QueryParseException e) {
@@ -120,7 +120,7 @@ public interface Index<K, V> {
    */
   default Optional<FieldBundle> getRaw(K key, QueryOptions opts) throws IOException {
     opts = opts.withStart(0).withLimit(2);
-    List<FieldBundle> results;
+    ImmutableList<FieldBundle> results;
     try {
       results = getSource(keyPredicate(key), opts).readRaw().toList();
     } catch (QueryParseException e) {
diff --git a/java/com/google/gerrit/index/project/IndexedProjectQuery.java b/java/com/google/gerrit/index/project/IndexedProjectQuery.java
index 4409ccbc34..383ba1c75d 100644
--- a/java/com/google/gerrit/index/project/IndexedProjectQuery.java
+++ b/java/com/google/gerrit/index/project/IndexedProjectQuery.java
@@ -15,9 +15,9 @@
 package com.google.gerrit.index.project;
 
 import com.google.gerrit.index.Index;
-import com.google.gerrit.index.IndexedQuery;
 import com.google.gerrit.index.QueryOptions;
 import com.google.gerrit.index.query.DataSource;
+import com.google.gerrit.index.query.IndexedQuery;
 import com.google.gerrit.index.query.Predicate;
 import com.google.gerrit.index.query.QueryParseException;
 import com.google.gerrit.reviewdb.client.Project;
diff --git a/java/com/google/gerrit/index/query/AndSource.java b/java/com/google/gerrit/index/query/AndSource.java
index d1e1c30b09..649dc32a02 100644
--- a/java/com/google/gerrit/index/query/AndSource.java
+++ b/java/com/google/gerrit/index/query/AndSource.java
@@ -21,10 +21,8 @@ import com.google.common.base.Throwables;
 import com.google.common.collect.FluentIterable;
 import com.google.common.collect.ImmutableList;
 import com.google.common.collect.Iterables;
-import com.google.gwtorm.server.ListResultSet;
 import com.google.gwtorm.server.OrmException;
 import com.google.gwtorm.server.OrmRuntimeException;
-import com.google.gwtorm.server.ResultSet;
 import java.util.ArrayList;
 import java.util.Collection;
 import java.util.Comparator;
diff --git a/java/com/google/gerrit/index/query/DataSource.java b/java/com/google/gerrit/index/query/DataSource.java
index 88cc0e3c0e..a82337f1b4 100644
--- a/java/com/google/gerrit/index/query/DataSource.java
+++ b/java/com/google/gerrit/index/query/DataSource.java
@@ -15,7 +15,6 @@
 package com.google.gerrit.index.query;
 
 import com.google.gwtorm.server.OrmException;
-import com.google.gwtorm.server.ResultSet;
 
 public interface DataSource<T> {
   /** @return an estimate of the number of results from {@link #read()}. */
diff --git a/java/com/google/gerrit/index/IndexedQuery.java b/java/com/google/gerrit/index/query/IndexedQuery.java
similarity index 90%
rename from java/com/google/gerrit/index/IndexedQuery.java
rename to java/com/google/gerrit/index/query/IndexedQuery.java
index 143cc26a0e..8df46a7b30 100644
--- a/java/com/google/gerrit/index/IndexedQuery.java
+++ b/java/com/google/gerrit/index/query/IndexedQuery.java
@@ -12,18 +12,13 @@
 // See the License for the specific language governing permissions and
 // limitations under the License.
 
-package com.google.gerrit.index;
+package com.google.gerrit.index.query;
 
 import com.google.common.base.MoreObjects;
 import com.google.common.collect.ImmutableList;
-import com.google.gerrit.index.query.DataSource;
-import com.google.gerrit.index.query.FieldBundle;
-import com.google.gerrit.index.query.IndexPredicate;
-import com.google.gerrit.index.query.Paginated;
-import com.google.gerrit.index.query.Predicate;
-import com.google.gerrit.index.query.QueryParseException;
+import com.google.gerrit.index.Index;
+import com.google.gerrit.index.QueryOptions;
 import com.google.gwtorm.server.OrmException;
-import com.google.gwtorm.server.ResultSet;
 import java.util.Collection;
 import java.util.List;
 
diff --git a/java/com/google/gerrit/index/query/ListResultSet.java b/java/com/google/gerrit/index/query/ListResultSet.java
new file mode 100644
index 0000000000..4cf48c8f1b
--- /dev/null
+++ b/java/com/google/gerrit/index/query/ListResultSet.java
@@ -0,0 +1,47 @@
+// Copyright 2008 Google Inc.
+//
+// Licensed 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 com.google.gerrit.index.query;
+
+import com.google.common.collect.ImmutableList;
+import java.util.Iterator;
+import java.util.List;
+
+public class ListResultSet<T> implements ResultSet<T> {
+  private ImmutableList<T> items;
+
+  public ListResultSet(List<T> r) {
+    items = ImmutableList.copyOf(r);
+  }
+
+  @Override
+  public Iterator<T> iterator() {
+    return toList().iterator();
+  }
+
+  @Override
+  public ImmutableList<T> toList() {
+    if (items == null) {
+      throw new IllegalStateException("Results already obtained");
+    }
+    ImmutableList<T> r = items;
+    items = null;
+    return r;
+  }
+
+  @Override
+  public void close() {
+    items = null;
+  }
+}
diff --git a/java/com/google/gerrit/index/query/Paginated.java b/java/com/google/gerrit/index/query/Paginated.java
index 20f65dcf06..c11d8c7440 100644
--- a/java/com/google/gerrit/index/query/Paginated.java
+++ b/java/com/google/gerrit/index/query/Paginated.java
@@ -16,7 +16,6 @@ package com.google.gerrit.index.query;
 
 import com.google.gerrit.index.QueryOptions;
 import com.google.gwtorm.server.OrmException;
-import com.google.gwtorm.server.ResultSet;
 
 public interface Paginated<T> {
   QueryOptions getOptions();
diff --git a/java/com/google/gerrit/index/query/QueryProcessor.java b/java/com/google/gerrit/index/query/QueryProcessor.java
index 081575b631..6f10750955 100644
--- a/java/com/google/gerrit/index/query/QueryProcessor.java
+++ b/java/com/google/gerrit/index/query/QueryProcessor.java
@@ -30,7 +30,6 @@ import com.google.gerrit.index.Index;
 import com.google.gerrit.index.IndexCollection;
 import com.google.gerrit.index.IndexConfig;
 import com.google.gerrit.index.IndexRewriter;
-import com.google.gerrit.index.IndexedQuery;
 import com.google.gerrit.index.QueryOptions;
 import com.google.gerrit.index.SchemaDefinitions;
 import com.google.gerrit.metrics.Description;
@@ -40,7 +39,6 @@ import com.google.gerrit.metrics.Timer1;
 import com.google.gerrit.server.logging.CallerFinder;
 import com.google.gwtorm.server.OrmException;
 import com.google.gwtorm.server.OrmRuntimeException;
-import com.google.gwtorm.server.ResultSet;
 import java.util.ArrayList;
 import java.util.List;
 import java.util.Optional;
@@ -268,7 +266,7 @@ public abstract class QueryProcessor<T> {
 
       out = new ArrayList<>(cnt);
       for (int i = 0; i < cnt; i++) {
-        List<T> matchesList = matches.get(i).toList();
+        ImmutableList<T> matchesList = matches.get(i).toList();
         logger.atFine().log(
             "Matches[%d]:\n%s",
             i, lazy(() -> matchesList.stream().map(this::formatForLogging).collect(toSet())));
diff --git a/java/com/google/gerrit/index/query/QueryResult.java b/java/com/google/gerrit/index/query/QueryResult.java
index 341e2b60f7..33fcef0364 100644
--- a/java/com/google/gerrit/index/query/QueryResult.java
+++ b/java/com/google/gerrit/index/query/QueryResult.java
@@ -15,6 +15,7 @@
 package com.google.gerrit.index.query;
 
 import com.google.auto.value.AutoValue;
+import com.google.common.collect.ImmutableList;
 import com.google.gerrit.common.Nullable;
 import java.util.List;
 
@@ -22,15 +23,15 @@ import java.util.List;
 @AutoValue
 public abstract class QueryResult<T> {
   public static <T> QueryResult<T> create(
-      @Nullable String query, Predicate<T> predicate, int limit, List<T> entites) {
+      @Nullable String query, Predicate<T> predicate, int limit, List<T> entities) {
     boolean more;
-    if (entites.size() > limit) {
+    if (entities.size() > limit) {
       more = true;
-      entites = entites.subList(0, limit);
+      entities = entities.subList(0, limit);
     } else {
       more = false;
     }
-    return new AutoValue_QueryResult<>(query, predicate, entites, more);
+    return new AutoValue_QueryResult<>(query, predicate, ImmutableList.copyOf(entities), more);
   }
 
   /** @return the original query string, or null if the query was created programmatically. */
@@ -41,7 +42,7 @@ public abstract class QueryResult<T> {
   public abstract Predicate<T> predicate();
 
   /** @return the query results. */
-  public abstract List<T> entities();
+  public abstract ImmutableList<T> entities();
 
   /**
    * @return whether the query could be retried with a higher start/limit to produce more results.
diff --git a/java/com/google/gerrit/index/query/ResultSet.java b/java/com/google/gerrit/index/query/ResultSet.java
new file mode 100644
index 0000000000..65fcd4593c
--- /dev/null
+++ b/java/com/google/gerrit/index/query/ResultSet.java
@@ -0,0 +1,52 @@
+// Copyright 2008 Google Inc.
+//
+// Licensed 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 com.google.gerrit.index.query;
+
+import com.google.common.collect.ImmutableList;
+import java.util.Iterator;
+
+/**
+ * Result from any data store query function.
+ *
+ * @param <T> type of entity being returned by the query.
+ */
+public interface ResultSet<T> extends Iterable<T> {
+  /**
+   * Obtain an iterator to loop through the results.
+   *
+   * <p>The iterator can be obtained only once. When the iterator completes ( <code>hasNext()</code>
+   * returns false) {@link #close()} will be automatically called.
+   */
+  @Override
+  Iterator<T> iterator();
+
+  /**
+   * Materialize all results as a single list.
+   *
+   * <p>Prior to returning {@link #close()} is invoked. This method must not be combined with {@link
+   * #iterator()} on the same instance.
+   *
+   * @return immutable list of the complete results.
+   */
+  ImmutableList<T> toList();
+
+  /**
+   * Close the result, discarding any further results.
+   *
+   * <p>This method may be invoked more than once. Its main use is to stop obtaining results before
+   * the iterator has finished.
+   */
+  void close();
+}
diff --git a/java/com/google/gerrit/lucene/AbstractLuceneIndex.java b/java/com/google/gerrit/lucene/AbstractLuceneIndex.java
index 40acf80744..d9ca76ddd0 100644
--- a/java/com/google/gerrit/lucene/AbstractLuceneIndex.java
+++ b/java/com/google/gerrit/lucene/AbstractLuceneIndex.java
@@ -20,6 +20,7 @@ import static java.util.concurrent.TimeUnit.MILLISECONDS;
 
 import com.google.common.base.Joiner;
 import com.google.common.collect.ArrayListMultimap;
+import com.google.common.collect.ImmutableList;
 import com.google.common.collect.ListMultimap;
 import com.google.common.collect.Sets;
 import com.google.common.flogger.FluentLogger;
@@ -37,18 +38,15 @@ import com.google.gerrit.index.Schema;
 import com.google.gerrit.index.Schema.Values;
 import com.google.gerrit.index.query.DataSource;
 import com.google.gerrit.index.query.FieldBundle;
+import com.google.gerrit.index.query.ListResultSet;
+import com.google.gerrit.index.query.ResultSet;
 import com.google.gerrit.server.config.SitePaths;
 import com.google.gerrit.server.index.IndexUtils;
 import com.google.gerrit.server.logging.LoggingContextAwareExecutorService;
 import com.google.gerrit.server.logging.LoggingContextAwareScheduledExecutorService;
 import com.google.gwtorm.server.OrmException;
-import com.google.gwtorm.server.ResultSet;
 import java.io.IOException;
 import java.sql.Timestamp;
-import java.util.ArrayList;
-import java.util.Collections;
-import java.util.Iterator;
-import java.util.List;
 import java.util.Map;
 import java.util.Set;
 import java.util.concurrent.Callable;
@@ -494,32 +492,16 @@ public abstract class AbstractLuceneIndex<K, V> implements Index<K, V> {
         searcher = acquire();
         int realLimit = opts.start() + opts.limit();
         TopFieldDocs docs = searcher.search(query, realLimit, sort);
-        List<T> result = new ArrayList<>(docs.scoreDocs.length);
+        ImmutableList.Builder<T> b = ImmutableList.builderWithExpectedSize(docs.scoreDocs.length);
         for (int i = opts.start(); i < docs.scoreDocs.length; i++) {
           ScoreDoc sd = docs.scoreDocs[i];
           Document doc = searcher.doc(sd.doc, opts.fields());
           T mapperResult = mapper.apply(doc);
           if (mapperResult != null) {
-            result.add(mapperResult);
+            b.add(mapperResult);
           }
         }
-        final List<T> r = Collections.unmodifiableList(result);
-        return new ResultSet<T>() {
-          @Override
-          public Iterator<T> iterator() {
-            return r.iterator();
-          }
-
-          @Override
-          public List<T> toList() {
-            return r;
-          }
-
-          @Override
-          public void close() {
-            // Do nothing.
-          }
-        };
+        return new ListResultSet<>(b.build());
       } catch (IOException e) {
         throw new OrmException(e);
       } finally {
diff --git a/java/com/google/gerrit/lucene/LuceneChangeIndex.java b/java/com/google/gerrit/lucene/LuceneChangeIndex.java
index 938665692d..a3394c3fa6 100644
--- a/java/com/google/gerrit/lucene/LuceneChangeIndex.java
+++ b/java/com/google/gerrit/lucene/LuceneChangeIndex.java
@@ -28,6 +28,7 @@ import com.google.common.base.Function;
 import com.google.common.base.Throwables;
 import com.google.common.collect.Collections2;
 import com.google.common.collect.FluentIterable;
+import com.google.common.collect.ImmutableList;
 import com.google.common.collect.Iterables;
 import com.google.common.collect.ListMultimap;
 import com.google.common.collect.MultimapBuilder;
@@ -40,6 +41,7 @@ import com.google.gerrit.index.Schema;
 import com.google.gerrit.index.query.FieldBundle;
 import com.google.gerrit.index.query.Predicate;
 import com.google.gerrit.index.query.QueryParseException;
+import com.google.gerrit.index.query.ResultSet;
 import com.google.gerrit.proto.Protos;
 import com.google.gerrit.reviewdb.client.Account;
 import com.google.gerrit.reviewdb.client.Change;
@@ -62,7 +64,6 @@ import com.google.gerrit.server.query.change.ChangeData;
 import com.google.gerrit.server.query.change.ChangeDataSource;
 import com.google.gwtorm.server.OrmException;
 import com.google.gwtorm.server.OrmRuntimeException;
-import com.google.gwtorm.server.ResultSet;
 import com.google.inject.Inject;
 import com.google.inject.assistedinject.Assisted;
 import com.google.protobuf.MessageLite;
@@ -333,7 +334,8 @@ public class LuceneChangeIndex implements ChangeIndex {
       } catch (IOException e) {
         throw new OrmException(e);
       }
-      List<FieldBundle> fieldBundles = documents.stream().map(rawDocumentMapper).collect(toList());
+      ImmutableList<FieldBundle> fieldBundles =
+          documents.stream().map(rawDocumentMapper).collect(toImmutableList());
       return new ResultSet<FieldBundle>() {
         @Override
         public Iterator<FieldBundle> iterator() {
@@ -341,7 +343,7 @@ public class LuceneChangeIndex implements ChangeIndex {
         }
 
         @Override
-        public List<FieldBundle> toList() {
+        public ImmutableList<FieldBundle> toList() {
           return fieldBundles;
         }
 
@@ -401,15 +403,16 @@ public class LuceneChangeIndex implements ChangeIndex {
     }
 
     @Override
-    public List<ChangeData> toList() {
+    public ImmutableList<ChangeData> toList() {
       try {
         List<Document> docs = future.get();
-        List<ChangeData> result = new ArrayList<>(docs.size());
+        ImmutableList.Builder<ChangeData> result =
+            ImmutableList.builderWithExpectedSize(docs.size());
         String idFieldName = LEGACY_ID.getName();
         for (Document doc : docs) {
           result.add(toChangeData(fields(doc, fields), fields, idFieldName));
         }
-        return result;
+        return result.build();
       } catch (InterruptedException e) {
         close();
         throw new OrmRuntimeException(e);
diff --git a/java/com/google/gerrit/pgm/Daemon.java b/java/com/google/gerrit/pgm/Daemon.java
index e7e8ea359d..01c7685d4b 100644
--- a/java/com/google/gerrit/pgm/Daemon.java
+++ b/java/com/google/gerrit/pgm/Daemon.java
@@ -90,7 +90,6 @@ import com.google.gerrit.server.plugins.PluginGuiceEnvironment;
 import com.google.gerrit.server.plugins.PluginModule;
 import com.google.gerrit.server.project.DefaultProjectNameLockManager;
 import com.google.gerrit.server.restapi.RestApiModule;
-import com.google.gerrit.server.schema.InMemoryAccountPatchReviewStore;
 import com.google.gerrit.server.schema.JdbcAccountPatchReviewStore;
 import com.google.gerrit.server.schema.NoteDbSchemaVersionCheck;
 import com.google.gerrit.server.securestore.DefaultSecureStore;
@@ -404,10 +403,7 @@ public class Daemon extends SiteProgram {
     modules.add(new WorkQueue.Module());
     modules.add(new StreamEventsApiListener.Module());
     modules.add(new EventBroker.Module());
-    modules.add(
-        inMemoryTest
-            ? new InMemoryAccountPatchReviewStore.Module()
-            : new JdbcAccountPatchReviewStore.Module(config));
+    modules.add(new JdbcAccountPatchReviewStore.Module(config));
     modules.add(new SysExecutorModule());
     modules.add(new DiffExecutorModule());
     modules.add(new MimeUtil2Module());
diff --git a/java/com/google/gerrit/server/index/account/IndexedAccountQuery.java b/java/com/google/gerrit/server/index/account/IndexedAccountQuery.java
index 644f1ebae3..18f44f08af 100644
--- a/java/com/google/gerrit/server/index/account/IndexedAccountQuery.java
+++ b/java/com/google/gerrit/server/index/account/IndexedAccountQuery.java
@@ -17,9 +17,9 @@ package com.google.gerrit.server.index.account;
 import static com.google.common.base.Preconditions.checkState;
 
 import com.google.gerrit.index.Index;
-import com.google.gerrit.index.IndexedQuery;
 import com.google.gerrit.index.QueryOptions;
 import com.google.gerrit.index.query.DataSource;
+import com.google.gerrit.index.query.IndexedQuery;
 import com.google.gerrit.index.query.Matchable;
 import com.google.gerrit.index.query.Predicate;
 import com.google.gerrit.index.query.QueryParseException;
diff --git a/java/com/google/gerrit/server/index/change/IndexedChangeQuery.java b/java/com/google/gerrit/server/index/change/IndexedChangeQuery.java
index 66f8df2534..38ea730b51 100644
--- a/java/com/google/gerrit/server/index/change/IndexedChangeQuery.java
+++ b/java/com/google/gerrit/server/index/change/IndexedChangeQuery.java
@@ -19,25 +19,25 @@ import static com.google.gerrit.server.index.change.ChangeField.CHANGE;
 import static com.google.gerrit.server.index.change.ChangeField.PROJECT;
 
 import com.google.common.annotations.VisibleForTesting;
+import com.google.common.collect.ImmutableList;
 import com.google.common.collect.ImmutableSet;
 import com.google.common.collect.Iterables;
 import com.google.gerrit.index.IndexConfig;
-import com.google.gerrit.index.IndexedQuery;
 import com.google.gerrit.index.QueryOptions;
 import com.google.gerrit.index.query.DataSource;
 import com.google.gerrit.index.query.IndexPredicate;
+import com.google.gerrit.index.query.IndexedQuery;
 import com.google.gerrit.index.query.Matchable;
 import com.google.gerrit.index.query.Predicate;
 import com.google.gerrit.index.query.QueryParseException;
+import com.google.gerrit.index.query.ResultSet;
 import com.google.gerrit.reviewdb.client.Change;
 import com.google.gerrit.server.query.change.ChangeData;
 import com.google.gerrit.server.query.change.ChangeDataSource;
 import com.google.gwtorm.server.OrmException;
-import com.google.gwtorm.server.ResultSet;
 import java.util.HashMap;
 import java.util.HashSet;
 import java.util.Iterator;
-import java.util.List;
 import java.util.Map;
 import java.util.Set;
 
@@ -98,8 +98,8 @@ public class IndexedChangeQuery extends IndexedQuery<Change.Id, ChangeData>
       }
 
       @Override
-      public List<ChangeData> toList() {
-        List<ChangeData> r = rs.toList();
+      public ImmutableList<ChangeData> toList() {
+        ImmutableList<ChangeData> r = rs.toList();
         for (ChangeData cd : r) {
           fromSource.put(cd, currSource);
         }
diff --git a/java/com/google/gerrit/server/index/group/IndexedGroupQuery.java b/java/com/google/gerrit/server/index/group/IndexedGroupQuery.java
index 79f25c0861..32393b0687 100644
--- a/java/com/google/gerrit/server/index/group/IndexedGroupQuery.java
+++ b/java/com/google/gerrit/server/index/group/IndexedGroupQuery.java
@@ -16,9 +16,9 @@ package com.google.gerrit.server.index.group;
 
 import com.google.gerrit.index.Index;
 import com.google.gerrit.index.IndexConfig;
-import com.google.gerrit.index.IndexedQuery;
 import com.google.gerrit.index.QueryOptions;
 import com.google.gerrit.index.query.DataSource;
+import com.google.gerrit.index.query.IndexedQuery;
 import com.google.gerrit.index.query.Predicate;
 import com.google.gerrit.index.query.QueryParseException;
 import com.google.gerrit.reviewdb.client.AccountGroup;
diff --git a/java/com/google/gerrit/server/query/change/OrSource.java b/java/com/google/gerrit/server/query/change/OrSource.java
index b3e1c271ef..dcbf5170ab 100644
--- a/java/com/google/gerrit/server/query/change/OrSource.java
+++ b/java/com/google/gerrit/server/query/change/OrSource.java
@@ -15,12 +15,12 @@
 package com.google.gerrit.server.query.change;
 
 import com.google.gerrit.index.query.FieldBundle;
+import com.google.gerrit.index.query.ListResultSet;
 import com.google.gerrit.index.query.OrPredicate;
 import com.google.gerrit.index.query.Predicate;
+import com.google.gerrit.index.query.ResultSet;
 import com.google.gerrit.reviewdb.client.Change;
-import com.google.gwtorm.server.ListResultSet;
 import com.google.gwtorm.server.OrmException;
-import com.google.gwtorm.server.ResultSet;
 import java.util.ArrayList;
 import java.util.Collection;
 import java.util.HashSet;
diff --git a/java/com/google/gerrit/server/restapi/change/ReviewersUtil.java b/java/com/google/gerrit/server/restapi/change/ReviewersUtil.java
index 854125c933..75710c46fb 100644
--- a/java/com/google/gerrit/server/restapi/change/ReviewersUtil.java
+++ b/java/com/google/gerrit/server/restapi/change/ReviewersUtil.java
@@ -34,6 +34,7 @@ import com.google.gerrit.index.QueryOptions;
 import com.google.gerrit.index.query.FieldBundle;
 import com.google.gerrit.index.query.Predicate;
 import com.google.gerrit.index.query.QueryParseException;
+import com.google.gerrit.index.query.ResultSet;
 import com.google.gerrit.metrics.Description;
 import com.google.gerrit.metrics.Description.Units;
 import com.google.gerrit.metrics.MetricMaker;
@@ -57,7 +58,6 @@ import com.google.gerrit.server.project.ProjectState;
 import com.google.gerrit.server.query.account.AccountPredicates;
 import com.google.gerrit.server.query.account.AccountQueryBuilder;
 import com.google.gwtorm.server.OrmException;
-import com.google.gwtorm.server.ResultSet;
 import com.google.inject.Inject;
 import com.google.inject.Provider;
 import com.google.inject.Singleton;
diff --git a/java/com/google/gerrit/server/schema/InMemoryAccountPatchReviewStore.java b/java/com/google/gerrit/server/schema/InMemoryAccountPatchReviewStore.java
deleted file mode 100644
index 35e81b22dc..0000000000
--- a/java/com/google/gerrit/server/schema/InMemoryAccountPatchReviewStore.java
+++ /dev/null
@@ -1,58 +0,0 @@
-// Copyright (C) 2017 The Android Open Source Project
-//
-// Licensed 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 com.google.gerrit.server.schema;
-
-import com.google.common.annotations.VisibleForTesting;
-import com.google.gerrit.extensions.registration.DynamicItem;
-import com.google.gerrit.lifecycle.LifecycleModule;
-import com.google.gerrit.server.change.AccountPatchReviewStore;
-import com.google.gwtorm.jdbc.SimpleDataSource;
-import java.sql.SQLException;
-import java.util.Properties;
-import javax.sql.DataSource;
-
-public class InMemoryAccountPatchReviewStore extends JdbcAccountPatchReviewStore {
-  @VisibleForTesting
-  public static class Module extends LifecycleModule {
-    @Override
-    protected void configure() {
-      InMemoryAccountPatchReviewStore inMemoryStore = new InMemoryAccountPatchReviewStore();
-      DynamicItem.bind(binder(), AccountPatchReviewStore.class).toInstance(inMemoryStore);
-      listener().toInstance(inMemoryStore);
-    }
-  }
-
-  /**
-   * Creates an in-memory H2 database to store the reviewed flags. This should be used for tests
-   * only.
-   */
-  @VisibleForTesting
-  private InMemoryAccountPatchReviewStore() {
-    super(newDataSource());
-  }
-
-  private static synchronized DataSource newDataSource() {
-    final Properties p = new Properties();
-    p.setProperty("driver", "org.h2.Driver");
-    // DB_CLOSE_DELAY=-1: By default the content of an in-memory H2 database is lost at the moment
-    // the last connection is closed. This option keeps the content as long as the vm lives.
-    p.setProperty("url", "jdbc:h2:mem:account_patch_reviews;DB_CLOSE_DELAY=-1");
-    try {
-      return new SimpleDataSource(p);
-    } catch (SQLException e) {
-      throw new RuntimeException("Unable to create test datasource", e);
-    }
-  }
-}
diff --git a/java/com/google/gerrit/server/schema/JdbcAccountPatchReviewStore.java b/java/com/google/gerrit/server/schema/JdbcAccountPatchReviewStore.java
index 1ef69db8ed..fa4de40baa 100644
--- a/java/com/google/gerrit/server/schema/JdbcAccountPatchReviewStore.java
+++ b/java/com/google/gerrit/server/schema/JdbcAccountPatchReviewStore.java
@@ -17,6 +17,7 @@ package com.google.gerrit.server.schema;
 import static java.util.concurrent.TimeUnit.MILLISECONDS;
 import static java.util.concurrent.TimeUnit.SECONDS;
 
+import com.google.common.annotations.VisibleForTesting;
 import com.google.common.collect.ImmutableSet;
 import com.google.common.flogger.FluentLogger;
 import com.google.common.primitives.Ints;
@@ -48,6 +49,12 @@ public abstract class JdbcAccountPatchReviewStore
     implements AccountPatchReviewStore, LifecycleListener {
   private static final FluentLogger logger = FluentLogger.forEnclosingClass();
 
+  // DB_CLOSE_DELAY=-1: By default the content of an in-memory H2 database is lost at the moment the
+  // last connection is closed. This option keeps the content as long as the VM lives.
+  @VisibleForTesting
+  public static final String TEST_IN_MEMORY_URL =
+      "jdbc:h2:mem:account_patch_reviews;DB_CLOSE_DELAY=-1";
+
   private static final String ACCOUNT_PATCH_REVIEW_DB = "accountPatchReviewDb";
   private static final String H2_DB = "h2";
   private static final String MARIADB = "mariadb";
@@ -109,10 +116,6 @@ public abstract class JdbcAccountPatchReviewStore
     this.ds = createDataSource(cfg, sitePaths, threadSettingsConfig);
   }
 
-  protected JdbcAccountPatchReviewStore(DataSource ds) {
-    this.ds = ds;
-  }
-
   private static String getUrl(@GerritServerConfig Config cfg, SitePaths sitePaths) {
     String url = cfg.getString(ACCOUNT_PATCH_REVIEW_DB, null, URL);
     if (url == null) {
diff --git a/java/com/google/gerrit/testing/InMemoryModule.java b/java/com/google/gerrit/testing/InMemoryModule.java
index 681bbf3420..c8cea6f24f 100644
--- a/java/com/google/gerrit/testing/InMemoryModule.java
+++ b/java/com/google/gerrit/testing/InMemoryModule.java
@@ -77,7 +77,7 @@ import com.google.gerrit.server.permissions.DefaultPermissionBackendModule;
 import com.google.gerrit.server.plugins.ServerInformationImpl;
 import com.google.gerrit.server.project.DefaultProjectNameLockManager;
 import com.google.gerrit.server.restapi.RestApiModule;
-import com.google.gerrit.server.schema.InMemoryAccountPatchReviewStore;
+import com.google.gerrit.server.schema.JdbcAccountPatchReviewStore;
 import com.google.gerrit.server.schema.SchemaCreator;
 import com.google.gerrit.server.schema.SchemaCreatorImpl;
 import com.google.gerrit.server.securestore.DefaultSecureStore;
@@ -112,6 +112,8 @@ public class InMemoryModule extends FactoryModule {
   }
 
   public static void setDefaults(Config cfg) {
+    cfg.setString(
+        "accountPatchReviewDb", null, "url", JdbcAccountPatchReviewStore.TEST_IN_MEMORY_URL);
     cfg.setEnum("auth", null, "type", AuthType.DEVELOPMENT_BECOME_ANY_ACCOUNT);
     cfg.setString("gerrit", null, "allProjects", "Test-Projects");
     cfg.setString("gerrit", null, "basePath", "git");
@@ -215,7 +217,6 @@ public class InMemoryModule extends FactoryModule {
     install(new FakeEmailSender.Module());
     install(new SignedTokenEmailTokenVerifier.Module());
     install(new GpgModule(cfg));
-    install(new InMemoryAccountPatchReviewStore.Module());
     install(new LocalMergeSuperSetComputation.Module());
 
     bind(AllAccountsIndexer.class).toProvider(Providers.of(null));
diff --git a/javatests/com/google/gerrit/server/index/change/FakeChangeIndex.java b/javatests/com/google/gerrit/server/index/change/FakeChangeIndex.java
index d4ecb6df39..faee23311c 100644
--- a/javatests/com/google/gerrit/server/index/change/FakeChangeIndex.java
+++ b/javatests/com/google/gerrit/server/index/change/FakeChangeIndex.java
@@ -21,11 +21,11 @@ import com.google.gerrit.index.Schema;
 import com.google.gerrit.index.query.FieldBundle;
 import com.google.gerrit.index.query.Predicate;
 import com.google.gerrit.index.query.QueryParseException;
+import com.google.gerrit.index.query.ResultSet;
 import com.google.gerrit.reviewdb.client.Change;
 import com.google.gerrit.server.query.change.ChangeData;
 import com.google.gerrit.server.query.change.ChangeDataSource;
 import com.google.gwtorm.server.OrmException;
-import com.google.gwtorm.server.ResultSet;
 import org.junit.Ignore;
 
 @Ignore