diff --git a/java/com/google/gerrit/elasticsearch/AbstractElasticIndex.java b/java/com/google/gerrit/elasticsearch/AbstractElasticIndex.java
index 0d1f9cd..a21f9f5 100644
--- a/java/com/google/gerrit/elasticsearch/AbstractElasticIndex.java
+++ b/java/com/google/gerrit/elasticsearch/AbstractElasticIndex.java
@@ -26,6 +26,7 @@
 import com.google.common.collect.Lists;
 import com.google.common.collect.Streams;
 import com.google.common.flogger.FluentLogger;
+import com.google.common.io.BaseEncoding;
 import com.google.common.io.CharStreams;
 import com.google.gerrit.common.Nullable;
 import com.google.gerrit.elasticsearch.ElasticMapping.MappingProperties;
@@ -68,7 +69,6 @@
 import java.util.Map;
 import java.util.Set;
 import java.util.function.Function;
-import org.apache.commons.codec.binary.Base64;
 import org.apache.http.HttpEntity;
 import org.apache.http.HttpStatus;
 import org.apache.http.StatusLine;
@@ -88,7 +88,7 @@
   protected static final String SETTINGS = "settings";
 
   protected static byte[] decodeBase64(String base64String) {
-    return Base64.decodeBase64(base64String);
+    return BaseEncoding.base64().decode(base64String);
   }
 
   protected static <T> List<T> decodeProtos(
@@ -258,7 +258,7 @@
         } else if (type == FieldType.TIMESTAMP) {
           rawFields.put(element.getKey(), new Timestamp(inner.getAsLong()));
         } else if (type == FieldType.STORED_ONLY) {
-          rawFields.put(element.getKey(), Base64.decodeBase64(inner.getAsString()));
+          rawFields.put(element.getKey(), decodeBase64(inner.getAsString()));
         } else {
           throw FieldType.badFieldType(type);
         }
diff --git a/java/com/google/gerrit/elasticsearch/BUILD b/java/com/google/gerrit/elasticsearch/BUILD
index edbd82c..8bab80b 100644
--- a/java/com/google/gerrit/elasticsearch/BUILD
+++ b/java/com/google/gerrit/elasticsearch/BUILD
@@ -19,7 +19,6 @@
         "//lib:guava",
         "//lib:jgit",
         "//lib:protobuf",
-        "//lib/commons:codec",
         "//lib/commons:lang",
         "//lib/elasticsearch-rest-client",
         "//lib/flogger:api",
diff --git a/java/com/google/gerrit/elasticsearch/ElasticAccountIndex.java b/java/com/google/gerrit/elasticsearch/ElasticAccountIndex.java
index 374120e..33217bd 100644
--- a/java/com/google/gerrit/elasticsearch/ElasticAccountIndex.java
+++ b/java/com/google/gerrit/elasticsearch/ElasticAccountIndex.java
@@ -14,6 +14,7 @@
 
 package com.google.gerrit.elasticsearch;
 
+import com.google.common.collect.ImmutableSet;
 import com.google.gerrit.elasticsearch.ElasticMapping.MappingProperties;
 import com.google.gerrit.elasticsearch.bulk.BulkRequest;
 import com.google.gerrit.elasticsearch.bulk.IndexRequest;
@@ -72,7 +73,9 @@
 
   @Override
   public void replace(AccountState as) {
-    BulkRequest bulk = new IndexRequest(getId(as), indexName).add(new UpdateRequest<>(schema, as));
+    BulkRequest bulk =
+        new IndexRequest(getId(as), indexName)
+            .add(new UpdateRequest<>(schema, as, ImmutableSet.of()));
 
     String uri = getURI(type, BULK);
     Response response = postRequest(uri, bulk, getRefreshParam());
diff --git a/java/com/google/gerrit/elasticsearch/ElasticChangeIndex.java b/java/com/google/gerrit/elasticsearch/ElasticChangeIndex.java
index a658400..fe55eab 100644
--- a/java/com/google/gerrit/elasticsearch/ElasticChangeIndex.java
+++ b/java/com/google/gerrit/elasticsearch/ElasticChangeIndex.java
@@ -21,6 +21,7 @@
 
 import com.google.common.collect.FluentIterable;
 import com.google.common.collect.ImmutableListMultimap;
+import com.google.common.collect.ImmutableSet;
 import com.google.common.collect.Iterables;
 import com.google.common.collect.ListMultimap;
 import com.google.common.collect.Lists;
@@ -46,6 +47,8 @@
 import com.google.gerrit.server.ReviewerByEmailSet;
 import com.google.gerrit.server.ReviewerSet;
 import com.google.gerrit.server.StarredChangesUtil;
+import com.google.gerrit.server.change.MergeabilityComputationBehavior;
+import com.google.gerrit.server.config.GerritServerConfig;
 import com.google.gerrit.server.config.SitePaths;
 import com.google.gerrit.server.index.IndexUtils;
 import com.google.gerrit.server.index.change.ChangeField;
@@ -63,6 +66,7 @@
 import java.util.Optional;
 import java.util.Set;
 import org.apache.http.HttpStatus;
+import org.eclipse.jgit.lib.Config;
 import org.elasticsearch.client.Response;
 
 /** Secondary index implementation using Elasticsearch. */
@@ -89,6 +93,7 @@
   private final ChangeData.Factory changeDataFactory;
   private final Schema<ChangeData> schema;
   private final FieldDef<ChangeData, ?> idField;
+  private final ImmutableSet<String> skipFields;
 
   @Inject
   ElasticChangeIndex(
@@ -96,6 +101,7 @@
       ChangeData.Factory changeDataFactory,
       SitePaths sitePaths,
       ElasticRestClientProvider clientBuilder,
+      @GerritServerConfig Config gerritConfig,
       @Assisted Schema<ChangeData> schema) {
     super(cfg, sitePaths, schema, clientBuilder, CHANGES);
     this.changeDataFactory = changeDataFactory;
@@ -103,11 +109,16 @@
     this.mapping = new ChangeMapping(schema, client.adapter());
     this.idField =
         this.schema.useLegacyNumericFields() ? ChangeField.LEGACY_ID : ChangeField.LEGACY_ID_STR;
+    this.skipFields =
+        MergeabilityComputationBehavior.fromConfig(gerritConfig).includeInIndex()
+            ? ImmutableSet.of()
+            : ImmutableSet.of(ChangeField.MERGEABLE.getName());
   }
 
   @Override
   public void replace(ChangeData cd) {
-    BulkRequest bulk = new IndexRequest(getId(cd), indexName).add(new UpdateRequest<>(schema, cd));
+    BulkRequest bulk =
+        new IndexRequest(getId(cd), indexName).add(new UpdateRequest<>(schema, cd, skipFields));
 
     String uri = getURI(type, BULK);
     Response response = postRequest(uri, bulk, getRefreshParam());
@@ -238,7 +249,7 @@
 
     // Mergeable.
     JsonElement mergeableElement = source.get(ChangeField.MERGEABLE.getName());
-    if (mergeableElement != null) {
+    if (mergeableElement != null && !skipFields.contains(ChangeField.MERGEABLE.getName())) {
       String mergeable = mergeableElement.getAsString();
       if ("1".equals(mergeable)) {
         cd.setMergeable(true);
@@ -370,6 +381,15 @@
     // Unresolved-comment-count.
     decodeUnresolvedCommentCount(source, ChangeField.UNRESOLVED_COMMENT_COUNT.getName(), cd);
 
+    // Attention set.
+    if (fields.contains(ChangeField.ATTENTION_SET_FULL.getName())) {
+      ChangeField.parseAttentionSet(
+          FluentIterable.from(source.getAsJsonArray(ChangeField.ATTENTION_SET_FULL.getName()))
+              .transform(ElasticChangeIndex::decodeBase64JsonElement)
+              .toSet(),
+          cd);
+    }
+
     return cd;
   }
 
@@ -388,12 +408,16 @@
     }
     ChangeField.parseSubmitRecords(
         FluentIterable.from(records)
-            .transform(i -> new String(decodeBase64(i.getAsString()), UTF_8))
+            .transform(ElasticChangeIndex::decodeBase64JsonElement)
             .toList(),
         opts,
         out);
   }
 
+  private static String decodeBase64JsonElement(JsonElement input) {
+    return new String(decodeBase64(input.getAsString()), UTF_8);
+  }
+
   private void decodeUnresolvedCommentCount(JsonObject doc, String fieldName, ChangeData out) {
     JsonElement count = doc.get(fieldName);
     if (count == null) {
diff --git a/java/com/google/gerrit/elasticsearch/ElasticGroupIndex.java b/java/com/google/gerrit/elasticsearch/ElasticGroupIndex.java
index 3922f89..a16ec7f 100644
--- a/java/com/google/gerrit/elasticsearch/ElasticGroupIndex.java
+++ b/java/com/google/gerrit/elasticsearch/ElasticGroupIndex.java
@@ -14,6 +14,7 @@
 
 package com.google.gerrit.elasticsearch;
 
+import com.google.common.collect.ImmutableSet;
 import com.google.gerrit.elasticsearch.ElasticMapping.MappingProperties;
 import com.google.gerrit.elasticsearch.bulk.BulkRequest;
 import com.google.gerrit.elasticsearch.bulk.IndexRequest;
@@ -73,7 +74,8 @@
   @Override
   public void replace(InternalGroup group) {
     BulkRequest bulk =
-        new IndexRequest(getId(group), indexName).add(new UpdateRequest<>(schema, group));
+        new IndexRequest(getId(group), indexName)
+            .add(new UpdateRequest<>(schema, group, ImmutableSet.of()));
 
     String uri = getURI(type, BULK);
     Response response = postRequest(uri, bulk, getRefreshParam());
diff --git a/java/com/google/gerrit/elasticsearch/ElasticProjectIndex.java b/java/com/google/gerrit/elasticsearch/ElasticProjectIndex.java
index 7e45f4f..ed15e34 100644
--- a/java/com/google/gerrit/elasticsearch/ElasticProjectIndex.java
+++ b/java/com/google/gerrit/elasticsearch/ElasticProjectIndex.java
@@ -14,6 +14,7 @@
 
 package com.google.gerrit.elasticsearch;
 
+import com.google.common.collect.ImmutableSet;
 import com.google.gerrit.elasticsearch.ElasticMapping.MappingProperties;
 import com.google.gerrit.elasticsearch.bulk.BulkRequest;
 import com.google.gerrit.elasticsearch.bulk.IndexRequest;
@@ -31,12 +32,14 @@
 import com.google.gerrit.server.config.SitePaths;
 import com.google.gerrit.server.index.IndexUtils;
 import com.google.gerrit.server.project.ProjectCache;
+import com.google.gerrit.server.project.ProjectState;
 import com.google.gson.JsonArray;
 import com.google.gson.JsonElement;
 import com.google.gson.JsonObject;
 import com.google.inject.Inject;
 import com.google.inject.Provider;
 import com.google.inject.assistedinject.Assisted;
+import java.util.Optional;
 import java.util.Set;
 import org.apache.http.HttpStatus;
 import org.elasticsearch.client.Response;
@@ -74,7 +77,7 @@
   public void replace(ProjectData projectState) {
     BulkRequest bulk =
         new IndexRequest(projectState.getProject().getName(), indexName)
-            .add(new UpdateRequest<>(schema, projectState));
+            .add(new UpdateRequest<>(schema, projectState, ImmutableSet.of()));
 
     String uri = getURI(type, BULK);
     Response response = postRequest(uri, bulk, getRefreshParam());
@@ -118,6 +121,10 @@
 
     Project.NameKey nameKey =
         Project.nameKey(source.getAsJsonObject().get(ProjectField.NAME.getName()).getAsString());
-    return projectCache.get().get(nameKey).toProjectData();
+    Optional<ProjectState> state = projectCache.get().get(nameKey);
+    if (!state.isPresent()) {
+      return null;
+    }
+    return state.get().toProjectData();
   }
 }
diff --git a/java/com/google/gerrit/elasticsearch/bulk/UpdateRequest.java b/java/com/google/gerrit/elasticsearch/bulk/UpdateRequest.java
index 2f0bd01..196b8d6 100644
--- a/java/com/google/gerrit/elasticsearch/bulk/UpdateRequest.java
+++ b/java/com/google/gerrit/elasticsearch/bulk/UpdateRequest.java
@@ -16,6 +16,7 @@
 
 import static java.util.stream.Collectors.toList;
 
+import com.google.common.collect.ImmutableSet;
 import com.google.common.collect.Iterables;
 import com.google.common.collect.Streams;
 import com.google.gerrit.elasticsearch.builders.XContentBuilder;
@@ -27,17 +28,19 @@
 
   private final Schema<V> schema;
   private final V v;
+  private final ImmutableSet<String> skipFields;
 
-  public UpdateRequest(Schema<V> schema, V v) {
+  public UpdateRequest(Schema<V> schema, V v, ImmutableSet<String> skipFields) {
     this.schema = schema;
     this.v = v;
+    this.skipFields = skipFields;
   }
 
   @Override
   protected String getRequest() {
     try (XContentBuilder closeable = new XContentBuilder()) {
       XContentBuilder builder = closeable.startObject();
-      for (Values<V> values : schema.buildFields(v)) {
+      for (Values<V> values : schema.buildFields(v, skipFields)) {
         String name = values.getField().getName();
         if (values.getField().isRepeatable()) {
           builder.field(name, Streams.stream(values.getValues()).collect(toList()));