Method and system for data migration from network database to relational database

• US 5,930,806 A
• Filed: 12/04/1997
• Issued: 07/27/1999
• Est. Priority Date: 05/07/1997
• Status: Expired due to Term

• Current Assignee: Google LLC (Alphabet Inc.)
• Original Assignee: Fujitsu Limited
• Inventors: Hosoya, Takashi, Kamakura, Jyunichi, Haraguchi, Tadahiro, Sasakawa, Yoshinobu, Taira, Kazuki, Suzuki, Hiroshi, Enbutsu, Hisayuki
• Primary Examiner(s): Black, Thomas G.
• Assistant Examiner(s): Shah, Sanjiv
• Application Number:
  US08/985,080
• Time in Patent Office: 600 Days
• Field of Search: 707/204, 707/205, 707/2, 707/200, 707/201
• US Class Current: 1/1
• CPC Class Codes: G06F 16/214 Database migration support
• CPC Class Codes: Y10S 707/99953 Recoverability
• CPC Class Codes: Y10S 707/99955 Archiving or backup

Abstract

A data migration system that enables a database system to migrate from a network data model to a relational data model in a short development time, without degradation in data integrity. A record migration unit creates target records for the relational data model. The records are arranged in the same way as they originally were in the network data model before data migration has been made. A primary key addition unit then adds a primary key to each of the target records so that they can be uniquely identified. To preserve the original parent-child relationships between records, a relation key addition unit selects each child record from among the target records, identifies the parent of the child record by referring to the pointers added to corresponding source records, and gives a value of the primary key of the parent record to the child record as a relation key thereof. Further, a set sequence key addition unit gives set sequence keys to the child records so that they will represent a sequential order of the source records.

Claims

1. A data migration system for migrating a database from a network data model, where records are interrelated by pointers, to a relational data model, comprising:

record migration means for creating target records for the relational data model which are arranged in the same way that source records are originally arranged in the network data model;

primary key addition means for adding a primary key to each of the target records so as to uniquely identify the target records;

relation key addition means for selecting each child record from among the target records, identifying a parent record of the child record by referring to the pointers added to the source records, and giving a value of the primary key of the parent record to the child record as a relation key thereof; and

set sequence key addition means for giving set sequence keys to the child records so that the set sequence keys will represent a sequential order of the source records.

2. The data migration system according to claim 1, wherein said set sequence key addition means uses a code that represents a date and time when said set sequence key addition means has added the set sequence key, as the value of the set sequence key.

3. The data migration system according to claim 1, further comprising

data manipulation instruction converting means for converting a data manipulation instruction in an application program designed for the network data model into an instruction to manipulate the target records by using the primary keys, the relation keys, and the set sequence keys added thereto.

4. The data migration system according to claim 3, wherein said data manipulation instruction converting means converts a sequential retrieval instruction in the application program that searches for a particular child record in a sequential manner into an instruction that performs a sequential retrieval of the particular child record by referring to the set sequence keys of the child records whose relation keys coincide with the primary key of the parent record of the particular child record.

5. A computer-readable medium encoded with a computer program for migrating a database from a network data model, where records are interrelated by pointers, to a relational data model, the computer program being designed to run on a computer in order to cause the computer to function as:

record migration means for creating target records for the relational data model which are arranged in the same way that source records are originally arranged in the network data model;

primary key addition means for adding a primary key to each of the target records so as to uniquely identify the target records;

relation key addition means for selecting each child record from among the target records, identifying a parent record of the child record by referring to the pointers added to the source records, and giving a value of the primary key of the parent record to the child record as a relation key thereof; and

set sequence key addition means for giving set sequence keys to the child records so that the set sequence keys will represent a sequential order of the source records.

6. A method of migrating a database from a network data model, where records are interrelated by pointers, to a relational data model, comprising the steps of:

creating target records for the relational data model which are arranged in the same way that source records are originally arranged in the network data model;

adding a primary key to each of the target records so as to uniquely identify the target records;

for each child record selected from among the target records, identifying a parent record of the child record by referring to the pointers added to the source records, and giving a value of the primary key of the identified parent record to the child record as a relation key thereof; and

giving set sequence keys to the child records so that the set sequence keys will represent a sequential order of the source records.