To communicate with the database using NPs or CCU-type CPs, storage is automatically managed by TDP to balance performance with storage utilization. The amount of storage used varies with demand, storage being obtained, re-used, or freed according to internal algorithms, with all such storage available to any NP or CCU-type CP. The minimum and maximum amounts of storage that can be used varies with the number of such CPs and NPs that are STARTed and for CPs, the INITIAL IACMODE. The type of storage depends upon the INITIAL IACMODE specification, based on underlying operating system limitations. 31-bit storage fixed in real storage is used if the IACMODE is EXCPVR, IOSDRIVR, or DIAG98. Unlike the TDP cells, no configuration or tuning is required. However, the maximum can be limited by using fewer CPs or NPs, or for CPs by using IACMODE EXCP.