diff --git a/db_structure.xml b/db_structure.xml
index acdd2a5a57742c0ca059c76e827e0524a15d796f..99541a4f90110b43190a8bf6bcadc15faa9e58c1 100644
--- a/db_structure.xml
+++ b/db_structure.xml
@@ -1575,7 +1575,6 @@
 					<name>creation_timestamp</name>
 					<sorting>descending</sorting>
 				</field>
-				<!-- TODO: check whether this supports a query without creation timestamp -->
 			</index>
 
 			<index>
@@ -1635,17 +1634,25 @@
 			</field>
 
 			<index>
-				<name>comments_marker_user_id_index</name>
+				<name>comments_marker_object_index</name>
 				<unique>false</unique>
 				<field>
-					<name>user_id</name>
-					<sorting>descending</sorting>
+					<name>object_type</name>
+					<sorting>ascending</sorting>
+				</field>
+				<field>
+					<name>object_id</name>
+					<sorting>ascending</sorting>
 				</field>
 			</index>
 
 			<index>
-				<name>comments_marker_object_index</name>
-				<unique>false</unique>
+				<name>comments_marker_index</name>
+				<unique>true</unique>
+				<field>
+					<name>user_id</name>
+					<sorting>descending</sorting>
+				</field>
 				<field>
 					<name>object_type</name>
 					<sorting>ascending</sorting>
@@ -1654,7 +1661,6 @@
 					<name>object_id</name>
 					<sorting>ascending</sorting>
 				</field>
-				<!-- TODO: check whether this supports a query with user_id -->
 			</index>
 
 		</declaration>
diff --git a/version.php b/version.php
index 1113196ce33eee2dffa1db87206b2c47c2499483..d7b801421448b02323a82ef8cdb8d06c28f49f34 100644
--- a/version.php
+++ b/version.php
@@ -25,7 +25,7 @@
 // We only can count up. The 4. digit is only for the internal patchlevel to trigger DB upgrades
 // between betas, final and RCs. This is _not_ the public version number. Reset minor/patchlevel
 // when updating major/minor version number.
-$OC_Version = array(9, 0, 0, 14);
+$OC_Version = array(9, 0, 0, 15);
 
 // The human readable string
 $OC_VersionString = '9.0.0 beta 2';