Abstract: A memory management method, a memory storage device, and a memory control circuit unit are disclosed. The method is for a rewritable non-volatile memory module including first type physical units and second type physical units. The first type physical units adopt a first operation mode. The second type physical units adopt a second operation mode. The method includes: grouping a part of physical units in the second type physical units to a first reserved region and a second reserved region, and the physical units belonging to the first reserved region and the second reserved region are reserved for usage in a data merging operation; and performing a first data merging operation which includes: collecting first data from a source unit; selecting a target unit from the first reserved region or the second reserved region according to attribute of the source unit; and storing the first data to the target unit.

Abstract: A memory management method, a memory storage device and a memory control circuit unit are disclosed. The method includes: activating a data merge operation; selecting a plurality of first-type physical units and a second-type physical unit from a rewritable non-volatile memory module to execute the data merge operation, wherein a data capacity of each first-type physical unit is less than a data capacity of each second-type physical unit; during a first execution period of the data merge operation, copying first data from a first physical unit in a stable state among the first-type physical units to the second-type physical unit; and during the first execution period, storing second data from a host system to a second physical unit not in the stable state among the first-type physical units.