diff --git a/db/install.xml b/db/install.xml
index 72eee3a35f..8cd3f61e13 100755
--- a/db/install.xml
+++ b/db/install.xml
@@ -85,6 +85,7 @@
         <INDEX NAME="sessionid" UNIQUE="false" FIELDS="sessionid"/>
         <INDEX NAME="studentid" UNIQUE="false" FIELDS="studentid"/>
         <INDEX NAME="statusid" UNIQUE="false" FIELDS="statusid"/>
+        <INDEX NAME="sessionid_studentid_statusid" UNIQUE="false" FIELDS="sessionid, studentid, statusid"/>
       </INDEXES>
     </TABLE>
     <TABLE NAME="attendance_statuses" COMMENT="attendance_statuses table retrofitted from MySQL">
diff --git a/db/upgrade.php b/db/upgrade.php
index 31f7ec55df..917fb3e770 100755
--- a/db/upgrade.php
+++ b/db/upgrade.php
@@ -731,6 +731,13 @@ function xmldb_attendance_upgrade($oldversion=0) {
         upgrade_mod_savepoint(true, 2022083100, 'attendance');
     }
     if ($oldversion < 2022090900) {
+        $table = new xmldb_table('attendance_log');
+        $index = new xmldb_index('sessionid_studentid_statusid', XMLDB_KEY_UNIQUE, ['sessionid', 'studentid', 'statusid']);
+        // Conditionally launch add index sessionid_studentid_statusid.
+        if (!$dbman->index_exists($table, $index)) {
+            $dbman->add_index($table, $index);
+        }
+
         if (!empty($CFG->dbfamily) && $CFG->dbfamily == 'postgres') {
             $sql = 'DELETE FROM {attendance_log} a
                         WHERE a.id NOT IN (
@@ -814,5 +821,20 @@ function xmldb_attendance_upgrade($oldversion=0) {
         upgrade_mod_savepoint(true, 2023020106, 'attendance');
     }
 
+    if ($oldversion < 2023020109) {
+
+        // Add index on attendance_log for performance increase with update 2022090900.
+        $table = new xmldb_table('attendance_log');
+        $index = new xmldb_index('sessionid_studentid_statusid', XMLDB_KEY_UNIQUE, ['sessionid', 'studentid', 'statusid']);
+
+        // Conditionally launch add index sessionid_studentid_statusid.
+        if (!$dbman->index_exists($table, $index)) {
+            $dbman->add_index($table, $index);
+        }
+
+        // Attendance savepoint reached.
+        upgrade_mod_savepoint(true, 2023020109, 'attendance');
+    }
+
     return true;
 }
diff --git a/version.php b/version.php
index 11bb680b98..dc31ff3761 100755
--- a/version.php
+++ b/version.php
@@ -23,8 +23,8 @@
  */
 defined('MOODLE_INTERNAL') || die();
 
-$plugin->version   = 2023020108;
-$plugin->release   = 2023020108;
+$plugin->version   = 2023020109;
+$plugin->release   = 2023020109;
 $plugin->requires  = 2022090200; // Requires 4.1.
 $plugin->maturity  = MATURITY_STABLE;
 $plugin->cron      = 0;