Abstract: A storage area management method for a data storage apparatus partitions an acquired storage area into storage areas with differing power-of-2 sizes and manages each of them. Also, a storage area allocation method receives an allocation request for a storage area that includes a requested allocation size, and acquires an available storage area whose size is the smallest power-of-2 size encompassing the requested allocation size, and obtains a binary expression of the requested allocation size, and in response to the received allocation request, allocates a contiguous storage area comprised of storage areas each of whose size is a power of 2 of a value of a bit position wherein a 1 is set in the binary expression.

Abstract: The sort processing of keys to be sorted, which keys are expressed as bit strings involves a classification processing. In the classification processing, a bit string comparison between a reference key and a key which is an object of the classification is performed, and a difference bit position is obtained that is the bit position of the first bit that differs in the bit string comparison and the keys to be sorted are classified by the difference bit position into key groups with the same difference bit position.

Abstract: Using a tree configuration wherein node groups of four or more nodes composed of combinations of branch nodes, leaf nodes or empty nodes are linked into a tree form, a bit string search by a search key string is enabled by repeatedly linking to one of the nodes of a node group to which a primary node belongs in response to the bit values of keys of the search key string at the discrimination bit position included in the branch node.

Abstract: The sort processing of keys to be sorted, which keys are expressed as bit strings involves a classification processing. In the classification processing, a bit string comparison between a reference key and a key which is an object of the classification is performed, and a difference bit position is obtained that is the bit position of the first bit that differs in the bit string comparison and the keys to be sorted are classified by the difference bit position into key groups with the same difference bit position.

Abstract: A storage area management method for a data storage apparatus partitions an acquired storage area into storage areas with differing power-of-2 sizes and manages each of them. Also, a storage area allocation method receives an allocation request for a storage area that includes a requested allocation size, and acquires an available storage area whose size is the smallest power-of-2 size encompassing the requested allocation size, and obtains a binary expression of the requested allocation size, and in response to the received allocation request, allocates a contiguous storage area comprised of storage areas each of whose size is a power of 2 of a value of a bit position wherein a 1 is set in the binary expression.

Abstract: Using a tree configuration wherein node groups of four or more nodes composed of combinations of branch nodes, leaf nodes or empty nodes are linked into a tree form, a bit string search by a search key string is enabled by repeatedly linking to one of the nodes of a node group to which a primary node belongs in response to the bit values of keys of the search key string at the discrimination bit position included in the branch node.