COMMAND CONVERSION SYSTEM FOR HIERACHICAL ORDER RETRIEVAL

PURPOSE:To reduce the operation load on a user side by performing command conversion on the basis of a conversion table loaded from a magnetic storage medium on a main memory. CONSTITUTION:When a hierachical structure type data base 1 is converted into a network structure type data base 2, the conversion table 7 which contains the hierachical order of record types 8 included in the data base 2 is generated on the magnetic storage medium 3. Further, when a command for hierachical retrieval is generated by a user program 4 to retrieve the data base 2, the table 7 corresponding to the data base 2 to be retrieved is loaded from the medium 3 to the main memory 6 previously. Then, when the command for hierachical order retrieval is generated by the program 4, a processor 5 accepts the command and then looks up the table 7 in the memory 6 to convert the command and retrieve the data base 2, and also return the retrieval result to the program 4.