src/Pure/General/sql.scala

     def ::: (other: Tables): Tables = new Tables(other.list ::: list)
 
     def iterator: Iterator[Table] = list.iterator
 
     // requires transaction
-    def create_lock(db: Database): Unit = {
-      foreach(db.create_table(_))
-      lock(db)
-    }
-
-    // requires transaction
     def lock(db: Database, create: Boolean = false): Unit = {
       if (create) foreach(db.create_table(_))
       val sql = db.lock_tables(list)
       if (sql.nonEmpty) db.execute_statement(sql)
     }