diff --git a/lib/db/install.xml b/lib/db/install.xml
index e106f9c18fa..39761379cb0 100644
--- a/lib/db/install.xml
+++ b/lib/db/install.xml
@@ -1,5 +1,5 @@
 <?xml version="1.0" encoding="UTF-8" ?>
-<XMLDB PATH="lib/db" VERSION="20190122" COMMENT="XMLDB file for core Moodle tables"
+<XMLDB PATH="lib/db" VERSION="20190308" COMMENT="XMLDB file for core Moodle tables"
     xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
     xsi:noNamespaceSchemaLocation="../../lib/xmldb/xmldb.xsd"
 >
@@ -650,6 +650,20 @@
         <KEY NAME="userid" TYPE="foreign" FIELDS="userid" REFTABLE="user" REFFIELDS="id"/>
       </KEYS>
     </TABLE>
+    <TABLE NAME="message_conversation_actions" COMMENT="Stores all per-user actions on individual conversations">
+      <FIELDS>
+        <FIELD NAME="id" TYPE="int" LENGTH="10" NOTNULL="true" SEQUENCE="true"/>
+        <FIELD NAME="userid" TYPE="int" LENGTH="10" NOTNULL="true" SEQUENCE="false"/>
+        <FIELD NAME="conversationid" TYPE="int" LENGTH="10" NOTNULL="true" SEQUENCE="false"/>
+        <FIELD NAME="action" TYPE="int" LENGTH="10" NOTNULL="true" SEQUENCE="false"/>
+        <FIELD NAME="timecreated" TYPE="int" LENGTH="10" NOTNULL="true" SEQUENCE="false"/>
+      </FIELDS>
+      <KEYS>
+        <KEY NAME="primary" TYPE="primary" FIELDS="id"/>
+        <KEY NAME="userid" TYPE="foreign" FIELDS="userid" REFTABLE="user" REFFIELDS="id"/>
+        <KEY NAME="conversationid" TYPE="foreign" FIELDS="conversationid" REFTABLE="message_conversations" REFFIELDS="id"/>
+      </KEYS>
+    </TABLE>
     <TABLE NAME="message_user_actions" COMMENT="Stores all per-user actions on individual messages">
       <FIELDS>
         <FIELD NAME="id" TYPE="int" LENGTH="10" NOTNULL="true" SEQUENCE="true"/>
diff --git a/lib/db/upgrade.php b/lib/db/upgrade.php
index 51d51572fbb..851b7fdacd4 100644
--- a/lib/db/upgrade.php
+++ b/lib/db/upgrade.php
@@ -2753,5 +2753,31 @@ function xmldb_main_upgrade($oldversion) {
         upgrade_main_savepoint(true, 2019030100.01);
     }
 
+    if ($oldversion < 2019030800.00) {
+        // Define table 'message_conversation_actions' to be created.
+        // Note - I would have preferred 'message_conversation_user_actions' but due to Oracle we can't. Boo.
+        $table = new xmldb_table('message_conversation_actions');
+
+        // Adding fields to table 'message_conversation_actions'.
+        $table->add_field('id', XMLDB_TYPE_INTEGER, '10', null, XMLDB_NOTNULL, XMLDB_SEQUENCE, null);
+        $table->add_field('userid', XMLDB_TYPE_INTEGER, '10', null, XMLDB_NOTNULL, null, null);
+        $table->add_field('conversationid', XMLDB_TYPE_INTEGER, '10', null, XMLDB_NOTNULL, null, null);
+        $table->add_field('action', XMLDB_TYPE_INTEGER, '10', null, XMLDB_NOTNULL, null, null);
+        $table->add_field('timecreated', XMLDB_TYPE_INTEGER, '10', null, XMLDB_NOTNULL, null, null);
+
+        // Adding keys to table 'message_conversation_actions'.
+        $table->add_key('primary', XMLDB_KEY_PRIMARY, ['id']);
+        $table->add_key('userid', XMLDB_KEY_FOREIGN, ['userid'], 'user', ['id']);
+        $table->add_key('conversationid', XMLDB_KEY_FOREIGN, ['conversationid'], 'message_conversations', ['id']);
+
+        // Conditionally launch create table for 'message_conversation_actions'.
+        if (!$dbman->table_exists($table)) {
+            $dbman->create_table($table);
+        }
+
+        // Main savepoint reached.
+        upgrade_main_savepoint(true, 2019030800.00);
+    }
+
     return true;
 }
diff --git a/version.php b/version.php
index acfa8ec784c..a1bca9e9aee 100644
--- a/version.php
+++ b/version.php
@@ -29,7 +29,7 @@
 
 defined('MOODLE_INTERNAL') || die();
 
-$version  = 2019030700.00;              // YYYYMMDD      = weekly release date of this DEV branch.
+$version  = 2019030800.00;              // YYYYMMDD      = weekly release date of this DEV branch.
                                         //         RR    = release increments - 00 in DEV branches.
                                         //           .XX = incremental changes.