The amount of memory available for record-based data storage varies from device to device. The MIDP specification requires devices to reserve at least 8K of non-volatile memory for persistent data storage. The specification does not place any limits on the size of an individual record, but space constraints will vary from device to device. RMS provides methods for determining the size of an individual record, the total size of a record store, and how much memory for data storage remains. Remember that persistent memory is a shared, scarce resource, so be frugal in its use.