Data processing apparatus and computer-readable storage medium storing program for data processing

A data processing apparatus comprising:

• a memory configured to store a data set including a plurality of data elements and a first Bloom filter used in a membership test to determine whether a query-target data element is present in the data set and having specific bits set to a specific value, the specific bits being determined by predetermined calculation using the plurality of data elements, respectively;
• and
• a processor configured to execute a process including:
• deleting, when some data elements are deleted from the data set, a first bit array from a high order end of the first Bloom filter, the first bit array having a number of bits corresponding to a number of the some data elements;
• adding, when a first data element is entered as the query-target data element, a second bit array temporarily at a high order end of a second Bloom filter, which is obtained by the deleting of the first bit array from the first Bloom filter, the second bit array having a same number of bits as the first bit array, with all bits set to the specific value;
• and
• running the membership test, using the second Bloom filter with the second bit array added thereto, to determine whether the first data element is present in the data set from which the some data elements have been deleted.