diff --git a/net/server/group-mgr.c b/net/server/group-mgr.c
index 81fbd13..43bdb7e 100644
--- a/net/server/group-mgr.c
+++ b/net/server/group-mgr.c
@@ -130,7 +130,7 @@ static int check_db_table (CcnetGroupManager *manager, CcnetDB *db)
 
         sql = "CREATE TABLE IF NOT EXISTS GroupStructure ( "
               "id BIGINT NOT NULL PRIMARY KEY AUTO_INCREMENT, group_id INTEGER, "
-              "path VARCHAR(1024), UNIQUE INDEX(group_id))ENGINE=INNODB";
+              "path VARCHAR(1024), UNIQUE INDEX(group_id), UNIQUE INDEX(path))ENGINE=INNODB";
         if (ccnet_db_query (db, sql) < 0)
             return -1;
     } else if (db_type == CCNET_DB_TYPE_SQLITE) {
@@ -168,6 +168,12 @@ static int check_db_table (CcnetGroupManager *manager, CcnetDB *db)
               "path VARCHAR(1024))";
         if (ccnet_db_query (db, sql) < 0)
             return -1;
+
+        sql = "CREATE UNIQUE INDEX IF NOT EXISTS path_indx on "
+            "`GroupStructure` (`path`)";
+        if (ccnet_db_query (db, sql) < 0)
+            return -1;
+
     } else if (db_type == CCNET_DB_TYPE_PGSQL) {
         g_string_printf (group_sql,
             "CREATE TABLE IF NOT EXISTS \"%s\" (group_id SERIAL"
@@ -200,6 +206,13 @@ static int check_db_table (CcnetGroupManager *manager, CcnetDB *db)
               "path VARCHAR(1024))";
         if (ccnet_db_query (db, sql) < 0)
             return -1;
+
+        if (!pgsql_index_exists (db, "structure_path_idx")) {
+            sql = "CREATE UNIQUE structure_path_idx ON GroupStructure (path)";
+            if (ccnet_db_query (db, sql) < 0)
+                return -1;
+        }
+
     }
     g_string_free (group_sql, TRUE);