Memory controller and operating method thereof

A method of operating a memory controller controlling a memory device, the method comprising:

• receiving first data from a host;
• generating a mapping relationship of the first data on the basis of a first stream ID included in the first data;
• outputting a program command for storing the first data in the memory device on the basis of the mapping relationship;
• receiving second data for updating the first data from the host;
• and
• determining a second stream ID to be assigned to the second data.

A memory system comprising:

• a memory device suitable for storing current data together with a current stream identification (ID) into a storage region corresponding to the current stream ID;
• and
• a controller suitable for:
• counting a number of times that a logical address is provided for updating the current data with updated data to generate a first number;
• counting a number of times that a garbage collection operation is performed on a storage area corresponding to the logical address to generate a second number;
• adjusting, in response to a request of updating the current data, a value of the current steam ID resulting in an adjusted stream ID based on the first and second numbers;
• controlling the memory device to store the updated data together with the adjusted stream ID in a storage region corresponding to the adjusted stream ID;
• and
• invalidating the current data together with the current stream ID.