Method and device of archiving database and method and device of retrieving archived database

A database archiving and retrieving device, comprising:

• at least one processor coupled to a memory, the at least one processor being configured to:
• select at least one record group including a plurality of records based on selection information on at least one of a time and a field value, from an original table of a database from which data is archivable;
• when a record group in the at least one selected record group has records the number of which exceeds a predetermined threshold value, divide the record group into a plurality of record groups such that each of the plurality of divided record groups has records the number of which is equal to or smaller than the predetermined threshold value;
• compress and create group compression data for every record group, with respect to each of at least one selected record group;
• store the group compression data and the selection information corresponding to the group compression data in a compression table of the database;
• and
• receive a retrieving condition for retrieving records from the compression table;
• determine a number of database (DB) retrieving processes for retrieving the records in parallel, based on a performance of a computer which is configured to perform retrieval and the number of group compression data corresponding to the selection information satisfying the retrieving condition;
• and
• retrieve the records satisfying the retrieving condition in parallel, based on the determined number of DB retrieving processes,
• wherein the determining of the number of DB retrieving processes includes:
• collecting computer performance information on at least one of a number of central processing units (CPUs) included in the computer, a capacity of a memory, and an input/output speed of a storage device;
• determining the number of group compression data corresponding to the selection information satisfying the received retrieving condition among the group compression data stored in the compression table;
• and
• determining the number of DB retrieving processes for retrieving the records in parallel, based on the collected computer performance information and the determined number of group compression data,
• wherein the retrieving of the records satisfying the retrieving condition in parallel includes:
• allocating at least one group compression data to each of the determined number of DB retrieving processes, based on the number of group compression data corresponding to the selection information satisfying the retrieving condition, so that all of the group compression data are allocated to all of the DB retrieving processes;
• and
• decompressing the at least one group compression data which is allocated for every DB retrieving process and retrieving the records satisfying the retrieving condition in parallel.