Efficient data property identification method for a flash memory

An efficient data property identification method for a flash memory is disclosed, which comprises the following steps: (a) according to a logical block address (LBA) corresponding to a write request of the flash memory, searching for corresponding K counters by means of K hash functions in a hash table; (b) determining whether a decay period operation is required to be performed to the hash table? if yes, following step (c), otherwise, following step (d); (c) performing the decay period operation to the hash table; (d) performing a status update operation of the hash table; (e) performing a hash table status check and determining whether data in the LBA corresponding to the flash memory are frequently updated. According to the hash table and hash functions defined by the corresponding LBA of the above flash memory, whenever the flash memory performs a write request, the effect of efficiently identifying data property of the flash memory could be achieved by means of the decay period operation, the status upda