3. The method of claim 1 , wherein, when the previous character column was matched to a signature substring of the signiture string pattern, the method further comprising: analyzing whether an external memory block address was called from a memory table in which the signature substring, which was matched to the previous character column, is stored; and when the external memory block address is called from the memory table in which the signature substring matched to the previous character column is stored, analyzing whether a substring stored in the called external memory block address is matched to the character column to be searched, and when the external memory block address was not called from the memory table in which the signature substring matched to the previous character column is stored, analyzing whether a substring stored in an internal memory block address corresponding to a character column hash value to be searched is matched to the character column to be searched.
3. The method of claim 1 , wherein, when the previous character column was matched to a signature substring of the signiture string pattern, the method further comprising: analyzing whether an external memory block address was called from a memory table in which the signature substring, which was matched to the previous character column, is stored; and when the external memory block address is called from the memory table in which the signature substring matched to the previous character column is stored, analyzing whether a substring stored in the called external memory block address is matched to the character column to be searched, and when the external memory block address was not called from the memory table in which the signature substring matched to the previous character column is stored, analyzing whether a substring stored in an internal memory block address corresponding to a character column hash value to be searched is matched to the character column to be searched. 4. The method of claim 3 , wherein, when a substring stored in the internal or external memory block is not matched to the character column to be searched when analyzing whether a substring stored in the internal or external memory block is matched to the character column to be searched, a matching process is stopped, and when a substring stored in the internal or external memory block is matched to the character column to be searched, analyzing whether the matched signature substring is the last substring in the corresponding signature substring.