diff --git a/db_structure.xml b/db_structure.xml
index 879bbcb48ad..5eef44d8e84 100644
--- a/db_structure.xml
+++ b/db_structure.xml
@@ -427,102 +427,6 @@
 
  </table>
 
- <table>
-
-  <name>*dbprefix*principalgroups</name>
-
-  <declaration>
-
-   <field>
-    <name>id</name>
-    <type>integer</type>
-    <default>0</default>
-    <notnull>true</notnull>
-    <autoincrement>1</autoincrement>
-    <unsigned>true</unsigned>
-    <length>4</length>
-   </field>
-
-   <field>
-    <name>principal_id</name>
-    <type>integer</type>
-    <default></default>
-    <notnull>true</notnull>
-    <unsigned>true</unsigned>
-    <length>4</length>
-   </field>
-
-   <field>
-    <name>member_id</name>
-    <type>integer</type>
-    <default></default>
-    <notnull>true</notnull>
-    <unsigned>true</unsigned>
-    <length>4</length>
-   </field>
-
-   <index>
-    <name>principals_members_index</name>
-    <unique>true</unique>
-    <field>
-     <name>principal_id</name>
-     <sorting>ascending</sorting>
-    </field>
-    <field>
-     <name>member_id</name>
-     <sorting>ascending</sorting>
-    </field>
-   </index>
-
-  </declaration>
-
- </table>
-
- <table>
-
-  <name>*dbprefix*principals</name>
-
-  <declaration>
-
-   <field>
-    <name>id</name>
-    <type>integer</type>
-    <default>0</default>
-    <notnull>true</notnull>
-    <autoincrement>1</autoincrement>
-    <unsigned>true</unsigned>
-    <length>4</length>
-   </field>
-
-   <field>
-    <name>uri</name>
-    <type>text</type>
-    <default></default>
-    <notnull>false</notnull>
-    <length>255</length>
-   </field>
-
-   <field>
-    <name>displayname</name>
-    <type>text</type>
-    <default></default>
-    <notnull>false</notnull>
-    <length>255</length>
-   </field>
-
-   <index>
-    <name>uri</name>
-    <unique>true</unique>
-    <field>
-     <name>uri</name>
-     <sorting>ascending</sorting>
-    </field>
-   </index>
-
-  </declaration>
-
- </table>
-
  <table>
 
   <name>*dbprefix*properties</name>