1. A computer-implemented method comprising: determining a unit physical I/O (PIO) mis-estimation based on a proportion between an estimated PIO cost and an estimated logical I/O operations (LIO) cost, and a proportion between an actual PIO cost and an actual LIO cost; determining a current compensated PIO cost utilizing the unit PIO mis-estimation; and generating new compensated PIO cost values, indicative of PIO operations and memory I/O operations, by averaging the current compensated PIO cost value over multiple iterations; utilizing the new compensated PIO cost values as feedback to a query optimizer of the DBMS that selects query execution plans for future queries.