Adding idx_itemprop_id_tool index see #5357

main/install/install.lib.php

@@ -3070,7 +3070,8 @@ function create_course_tables($course_db_name = null) {
         PRIMARY KEY (c_id, id)
         )" . $charset_clause);
 
-    Database::query("ALTER TABLE `$TABLEITEMPROPERTY` ADD INDEX idx_item_property_toolref (tool,ref)");
+    Database::query("ALTER TABLE `$TABLEITEMPROPERTY` ADD INDEX idx_item_property_toolref (tool, ref)");
+    Database::query("ALTER TABLE `$TABLEITEMPROPERTY` ADD INDEX idx_itemprop_id_tool (c_id, tool(8))");
 
     /*           Tool introductions    */
     Database::query("

main/install/migrate-db-1.9.0-1.10.0-pre.sql

@@ -48,6 +48,7 @@ CREATE TABLE IF NOT EXISTS session_field_options (id int NOT NULL auto_increment
 
 ALTER TABLE c_lp_item ADD INDEX idx_c_lp_item_cid_lp_id (c_id, lp_id);
 ALTER TABLE c_lp_item_view ADD INDEX idx_c_lp_item_view_cid_lp_view_id_lp_item_id(c_id, lp_view_id, lp_item_id);
+ALTER TABLE c_item_property ADD INDEX idx_itemprop_id_tool (c_id, tool(8));
 ALTER TABLE c_tool_intro MODIFY COLUMN intro_text MEDIUMTEXT NOT NULL;
 
 -- Do not move this