Provided is a method for managing a shared memory in a database server. The database server includes a shared memory manager which divides a shared memory into a plurality of memory chunks to manage the memory chunks and allocates at least one memory chunk to a cache memory manager based on a request of the cache memory manager; a cache memory manager which requests at least one of the plurality of memory chunks to the shared memory manager, wherein the database server includes a plurality of cache memory managers and the database server uses the memory chunk which is allocated to the cache memory manager as a cache memory having a predetermined purpose, and the predetermined purposes of the plurality of cache memory managers are different from each other; and a main processor which performs a database operation using the cache memory.