diff --git a/Core/src/org/sleuthkit/autopsy/timeline/db/EventDB.java b/Core/src/org/sleuthkit/autopsy/timeline/db/EventDB.java
index 1beacbbf41..e939428dce 100644
--- a/Core/src/org/sleuthkit/autopsy/timeline/db/EventDB.java
+++ b/Core/src/org/sleuthkit/autopsy/timeline/db/EventDB.java
@@ -413,10 +413,7 @@ public class EventDB {
         try (ResultSet rs = getDataSourceIDsStmt.executeQuery()) {
             while (rs.next()) {
                 long datasourceID = rs.getLong("datasource_id");
-                //this relies on the fact that no tskObj has ID 0 but 0 is the default value for the datasource_id column in the events table.
-                if (datasourceID != 0) {
-                    hashSet.add(datasourceID);
-                }
+                hashSet.add(datasourceID);
             }
         } catch (SQLException ex) {
             LOGGER.log(Level.SEVERE, "Failed to get MAX time.", ex); // NON-NLS
@@ -583,6 +580,10 @@ public class EventDB {
 
             initializeTagsTable();
 
+            createIndex("events", Arrays.asList("datasource_id"));
+            createIndex("events", Arrays.asList("event_id", "hash_hit"));
+            createIndex("events", Arrays.asList("event_id", "tagged"));
+            createIndex("events", Arrays.asList("file_id"));
             createIndex("events", Arrays.asList("file_id"));
             createIndex("events", Arrays.asList("artifact_id"));
             createIndex("events", Arrays.asList("time"));
@@ -595,7 +596,7 @@ public class EventDB {
                         "INSERT INTO events (datasource_id,file_id ,artifact_id, time, sub_type, base_type, full_description, med_description, short_description, known_state, hash_hit, tagged) " // NON-NLS
                         + "VALUES (?,?,?,?,?,?,?,?,?,?,?,?)"); // NON-NLS
                 getHashSetNamesStmt = prepareStatement("SELECT hash_set_id, hash_set_name FROM hash_sets"); // NON-NLS
-                getDataSourceIDsStmt = prepareStatement("SELECT DISTINCT datasource_id FROM events"); // NON-NLS
+                getDataSourceIDsStmt = prepareStatement("SELECT DISTINCT datasource_id FROM events WHERE datasource_id != 0"); // NON-NLS
                 getMaxTimeStmt = prepareStatement("SELECT Max(time) AS max FROM events"); // NON-NLS
                 getMinTimeStmt = prepareStatement("SELECT Min(time) AS min FROM events"); // NON-NLS
                 getEventByIDStmt = prepareStatement("SELECT * FROM events WHERE event_id =  ?"); // NON-NLS
@@ -1041,7 +1042,7 @@ public class EventDB {
      *         the supplied filter, aggregated according to the given event type
      *         and description zoom levels
      */
-    List<EventCluster> getAggregatedEvents(ZoomParams params) {
+    List<EventCluster> getClusteredEvents(ZoomParams params) {
         //unpack params
         Interval timeRange = params.getTimeRange();
         RootFilter filter = params.getFilter();
@@ -1079,7 +1080,7 @@ public class EventDB {
         try (Statement createStatement = con.createStatement();
                 ResultSet rs = createStatement.executeQuery(query)) {
             while (rs.next()) {
-                events.add(aggregateEventHelper(rs, useSubTypes, descriptionLOD, filter.getTagsFilter()));
+                events.add(eventClusterHelper(rs, useSubTypes, descriptionLOD, filter.getTagsFilter()));
             }
         } catch (SQLException ex) {
             LOGGER.log(Level.SEVERE, "Failed to get aggregate events with query: " + query, ex); // NON-NLS
@@ -1087,11 +1088,11 @@ public class EventDB {
             DBLock.unlock();
         }
 
-        return mergeAggregateEvents(rangeInfo.getPeriodSize().getPeriod(), events);
+        return mergeEventClusters(rangeInfo.getPeriodSize().getPeriod(), events);
     }
 
     /**
-     * map a single row in a ResultSet to an AggregateEvent
+     * map a single row in a ResultSet to an EventCluster
      *
      * @param rs             the result set whose current row should be mapped
      * @param useSubTypes    use the sub_type column if true, else use the
@@ -1103,7 +1104,7 @@ public class EventDB {
      *
      * @throws SQLException
      */
-    private EventCluster aggregateEventHelper(ResultSet rs, boolean useSubTypes, DescriptionLOD descriptionLOD, TagsFilter filter) throws SQLException {
+    private EventCluster eventClusterHelper(ResultSet rs, boolean useSubTypes, DescriptionLOD descriptionLOD, TagsFilter filter) throws SQLException {
         Interval interval = new Interval(rs.getLong("min(time)") * 1000, rs.getLong("max(time)") * 1000, TimeLineController.getJodaTimeZone());// NON-NLS
         String eventIDsString = rs.getString("event_ids");// NON-NLS
         Set<Long> eventIDs = SQLHelper.unGroupConcat(eventIDsString, Long::valueOf);
@@ -1111,20 +1112,20 @@ public class EventDB {
         EventType type = useSubTypes ? RootEventType.allTypes.get(rs.getInt("sub_type")) : BaseTypes.values()[rs.getInt("base_type")];// NON-NLS
 
         Set<Long> hashHits = new HashSet<>();
-        String hashHitQuery = "SELECT group_concat(event_id) FROM events WHERE event_id IN (" + eventIDsString + ")  AND hash_hit = 1";// NON-NLS
+        String hashHitQuery = "SELECT event_id FROM events WHERE event_id IN (" + eventIDsString + ")  AND hash_hit = 1";// NON-NLS
         try (Statement stmt = con.createStatement();
                 ResultSet hashHitsRS = stmt.executeQuery(hashHitQuery)) {
             while (hashHitsRS.next()) {
-                hashHits = SQLHelper.unGroupConcat(hashHitsRS.getString("group_concat(event_id)"), Long::valueOf);// NON-NLS
+                hashHits.add(hashHitsRS.getLong("event_id"));
             }
         }
 
         Set<Long> tagged = new HashSet<>();
-        String taggedQuery = "SELECT group_concat(event_id) FROM events WHERE event_id IN (" + eventIDsString + ")  AND tagged = 1";// NON-NLS
+        String taggedQuery = "SELECT event_id FROM events WHERE event_id IN (" + eventIDsString + ")  AND tagged = 1";// NON-NLS
         try (Statement stmt = con.createStatement();
                 ResultSet taggedRS = stmt.executeQuery(taggedQuery)) {
             while (taggedRS.next()) {
-                tagged = SQLHelper.unGroupConcat(taggedRS.getString("group_concat(event_id)"), Long::valueOf);// NON-NLS
+                tagged.add(taggedRS.getLong("event_id"));
             }
         }
 
@@ -1145,7 +1146,7 @@ public class EventDB {
      *
      * @return
      */
-    static private List<EventCluster> mergeAggregateEvents(Period timeUnitLength, List<EventCluster> preMergedEvents) {
+    static private List<EventCluster> mergeEventClusters(Period timeUnitLength, List<EventCluster> preMergedEvents) {
 
         //effectively map from type to (map from description to events)
         Map<EventType, SetMultimap< String, EventCluster>> typeMap = new HashMap<>();
diff --git a/Core/src/org/sleuthkit/autopsy/timeline/db/EventsRepository.java b/Core/src/org/sleuthkit/autopsy/timeline/db/EventsRepository.java
index 1a9e61c2d1..bae051b66e 100644
--- a/Core/src/org/sleuthkit/autopsy/timeline/db/EventsRepository.java
+++ b/Core/src/org/sleuthkit/autopsy/timeline/db/EventsRepository.java
@@ -149,7 +149,7 @@ public class EventsRepository {
         aggregateEventsCache = CacheBuilder.newBuilder()
                 .maximumSize(1000L)
                 .expireAfterAccess(10, TimeUnit.MINUTES
-                ).build(CacheLoader.from(eventDB::getAggregatedEvents));
+                ).build(CacheLoader.from(eventDB::getClusteredEvents));
         maxCache = CacheBuilder.newBuilder().build(CacheLoader.from(eventDB::getMaxTime));
         minCache = CacheBuilder.newBuilder().build(CacheLoader.from(eventDB::getMinTime));
         this.modelInstance = new FilteredEventsModel(this, currentStateProperty);