diff --git a/src/org/labkey/snd/query/EventNotesDataIterator.java b/src/org/labkey/snd/query/EventNotesDataIterator.java
new file mode 100644
index 0000000..a1bea49
--- /dev/null
+++ b/src/org/labkey/snd/query/EventNotesDataIterator.java
@@ -0,0 +1,92 @@
+package org.labkey.snd.query;
+
+import org.apache.logging.log4j.Logger;
+import org.labkey.api.data.ColumnInfo;
+import org.labkey.api.data.Container;
+import org.labkey.api.data.DbScope;
+import org.labkey.api.dataiterator.AbstractDataIterator;
+import org.labkey.api.dataiterator.DataIterator;
+import org.labkey.api.dataiterator.DataIteratorContext;
+import org.labkey.api.dataiterator.DataIteratorUtil;
+import org.labkey.api.query.BatchValidationException;
+import org.labkey.api.query.UserSchema;
+import org.labkey.api.security.User;
+import org.labkey.api.util.logging.LogHelper;
+import org.labkey.snd.SNDManager;
+
+import java.io.IOException;
+import java.util.HashSet;
+import java.util.Set;
+
+public class EventNotesDataIterator extends AbstractDataIterator
+{
+    private static final SNDManager _sndManager = SNDManager.get();
+    private static final String EVENT_ID_COL = "eventId";
+    private static final String EVENT_NOTE_ID_COL = "eventNoteId";
+    private User _user;
+    private Container _container;
+    private int _eventIdColIndex;
+    private Set<Integer> _eventIds = new HashSet<>();
+    private DataIterator _in;
+    private Logger log = LogHelper.getLogger(EventNotesDataIterator.class, "Fill out event notes");
+
+    public static DataIterator wrap(DataIterator in, DataIteratorContext context, Container c, User u)
+    {
+        return new EventNotesDataIterator(in, context, c, u);
+    }
+
+    private EventNotesDataIterator(DataIterator in, DataIteratorContext context, Container c, User u)
+    {
+        super(context);
+        _user = u;
+        _container = c;
+        _in = in;
+
+        _eventIdColIndex = DataIteratorUtil.createColumnNameMap(in).get(EVENT_ID_COL);
+    }
+
+    @Override
+    public int getColumnCount()
+    {
+        return _in.getColumnCount();
+    }
+
+    @Override
+    public ColumnInfo getColumnInfo(int i)
+    {
+        return _in.getColumnInfo(i);
+    }
+
+    @Override
+    public boolean next() throws BatchValidationException
+    {
+        boolean hasNext = _in.next();
+        if (hasNext)
+        {
+            Integer eventId = (Integer)_in.get(_eventIdColIndex);
+            _eventIds.add(eventId);
+        }
+        else
+        {
+            UserSchema schema = SNDManager.getSndUserSchema(_container, _user);
+
+            // Add a post commit task to update the narrative cache after the transaction updating the notes is committed.
+            SNDManager.get().getTableInfo(schema, "EventNotes").getSchema().getScope().addCommitTask(() -> {
+                _sndManager.updateNarrativeCache(_container, _user, _eventIds, log);
+            }, DbScope.CommitTaskOption.POSTCOMMIT);
+        }
+        return hasNext;
+    }
+
+    @Override
+    public Object get(int i)
+    {
+        return _in.get(i);
+    }
+
+    @Override
+    public void close() throws IOException
+    {
+        _in.close();
+    }
+}
diff --git a/src/org/labkey/snd/query/EventNotesDataIteratorBuilder.java b/src/org/labkey/snd/query/EventNotesDataIteratorBuilder.java
new file mode 100644
index 0000000..a3190fb
--- /dev/null
+++ b/src/org/labkey/snd/query/EventNotesDataIteratorBuilder.java
@@ -0,0 +1,33 @@
+package org.labkey.snd.query;
+
+import org.jetbrains.annotations.NotNull;
+import org.labkey.api.data.Container;
+import org.labkey.api.dataiterator.DataIterator;
+import org.labkey.api.dataiterator.DataIteratorBuilder;
+import org.labkey.api.dataiterator.DataIteratorContext;
+import org.labkey.api.dataiterator.DataIteratorUtil;
+import org.labkey.api.security.User;
+
+public class EventNotesDataIteratorBuilder implements DataIteratorBuilder
+{
+    private final DataIteratorBuilder in;
+    private final User user;
+    private final Container container;
+
+    public EventNotesDataIteratorBuilder(@NotNull DataIteratorBuilder in, User user, Container container)
+    {
+        this.in = in;
+        this.user = user;
+        this.container = container;
+    }
+
+    @Override
+    public DataIterator getDataIterator(DataIteratorContext context)
+    {
+        DataIterator it = in.getDataIterator(context);
+        DataIterator in = DataIteratorUtil.wrapMap(it, false);
+        return EventNotesDataIterator.wrap(in, context, container, user);
+    }
+}
+
+
diff --git a/src/org/labkey/snd/query/EventNotesTable.java b/src/org/labkey/snd/query/EventNotesTable.java
index 5b389dc..a0bd74d 100644
--- a/src/org/labkey/snd/query/EventNotesTable.java
+++ b/src/org/labkey/snd/query/EventNotesTable.java
@@ -39,8 +39,6 @@
 import java.util.Collections;
 import java.util.List;
 import java.util.Map;
-import java.util.Set;
-import java.util.stream.Collectors;
 
 public class EventNotesTable extends SimpleUserSchema.SimpleTable<SNDUserSchema>
 {
@@ -98,7 +96,7 @@ public int mergeRows(User user, Container container, DataIteratorBuilder rows, B
         {
             Logger log = SNDManager.getLogger(configParameters, EventNotesTable.class);
             // Large merge triggers importRows path
-            int result = 0;
+            int result;
             if (getRowCount(rows, configParameters, errors) > SNDManager.MAX_MERGE_ROWS)
             {
                 log.info("More than " + SNDManager.MAX_MERGE_ROWS + " rows. using importRows method.");
@@ -107,17 +105,9 @@ public int mergeRows(User user, Container container, DataIteratorBuilder rows, B
             else
             {
                 log.info("Merging rows.");
+                DataIteratorBuilder dib = new EventNotesDataIteratorBuilder(rows, user, container);
 
-                DataIteratorContext context = getDataIteratorContext(errors, QueryUpdateService.InsertOption.MERGE, configParameters);
-
-                Set<Integer> eventIds = rows.getDataIterator(context).stream()
-                        .filter(row -> row.containsKey("eventId"))
-                        .map(row -> (Integer) row.get("eventId"))
-                        .collect(Collectors.toSet());
-
-                result = super.mergeRows(user, container, rows, errors, configParameters, extraScriptContext);
-
-                _sndManager.updateNarrativeCache(container, user, eventIds, log);
+                result = super.mergeRows(user, container, dib, errors, configParameters, extraScriptContext);
             }
             return result;
         }