Memory system and operating method thereof

Abstract

A memory system includes a memory device for storing first and second mapping information associated with target logical addresses for an unmap command, and a controller for loading the first and second mapping information from the memory device, comparing a size of target map data corresponding to the target logical addresses with a threshold value, sorting a plurality of map segments mapped with a plurality of target logical groups including the target logical addresses, respectively, into a plurality of regions based on a result of the comparing, and performing an unmap operation on each of the map segments included in the regions, wherein the first mapping information includes information on mapping relationships between the plurality of map segments and the plurality of target logical groups, and the second mapping information includes information on mapping relationships between the target logical addresses and corresponding physical addresses.