Abstract: A hot-data-based decision-making method for using in a computer having a storage device that includes plural storage units. The method includes processing a new datum to obtain a new data fingerprint and at least two storage index values; and determining whether a datum in the storage unit corresponding to any of the storage index values matches the new datum, and if so, generating an update hotness score by updating a pre-stored hotness score of an old data fingerprint of an old datum, wherein the old datum is hot if the update hotness score is not lower than a hotness threshold score, or is cold if it is lower; or, otherwise, determining whether the storage unit is blank, and if so, simply storing the new data fingerprint into the storage unit, or, otherwise, replacing an existing data fingerprint in the storage unit with the new data fingerprint.