Database archiving method and device for creating index information and method and device of retrieving archived database including index information

A database archiving and retrieving device for a database (DB), the device comprising:

• at least one processor coupled to a memory, the at least processor being configured to:
• select at least one record group including a plurality of records from an original table of the database in which data is archived, based on information on a field value of each of the at least one record group;
• compress and create group compression data for the each of the at least one record group;
• store the group compression data and a stored key value which is uniquely assigned to the group compression data in a compression table of the database;
• store the field value and the stored key value corresponding to the each of the at least one record group in a group index table;
• delete the plurality of records included in the at least one selected record group from the original table;
• store a primary key value, key index information which is a position in the group compression data, and information on the stored key value corresponding to the group compression data, with respect to each of records included in the original table, in a key index table;
• when there is at least one connected table which is connected with the original table by means of the primary key, with respect to second group compression data which is created by compressing a plurality of records in the at least one connected table, retrieve a record having the same primary key value as a record including in the original table, among a plurality of records included in the second group compression data;
• and
• further store sub-index information which is a position in the second group compression data with respect to the retrieved record having the same primary key value on the key index table;
• and
• retrieve records satisfying a retrieving condition in parallel, based on a determined number of DB retrieving processes,
• wherein the retrieving of the records in parallel is performed further based on the stored key value, the key index information, the sub-index information, and the second group compression data.