A method for determining an index of an object in a sequence of objects, the method comprising the steps of: obtaining a unique identifier value of a given object O; obtaining a query definition Q of a sequence, the Q query including an order definition according to a parameter of the O object; constructing a Q′ query based on the Q query, the Q′ query being different from the Q query by having a reversed ordering of results, with respect to the Q query, and providing results having said parameter value of objects preceding or matching the parameter value of the object O in the sequence of objects in the Q query result set; executing the Q′ query by a query execution engine; checking whether the object O is present as the first item in Q′ result set and in case it is, obtaining the index of the O object in Q sequence by retrieving objects count of the Q′ result set.