Abstract:
In a switching system data inheritance method of controlling hardware on the basis of a first database storing various management data such as subscriber information to inherit switching system data for various types of call connection processing, change information indicating a change in structure from the first database to a second database which inherits data from the first database is created. Data constituting the first database is converted into new data having a new structure and constituting the second database on the basis of the created change information to store the converted data in the second database. A switching system data inheritance system is also disclosed.

Description:
BACKGROUND OF THE INVENTION 
     The present invention relates to a switching system data inheritance method and system and, more particularly, to a data inheritance method and system which are used to make a database inherit subscriber information and the like used in a switching system from a database when the database have different structures. 
     In general, various management data such as subscriber information used for call connection processing in a switching system are stored in a database to be managed as a software file (operation file), together with software programs for controlling various types of hardware constituting the switching system. When the database structure needs to be changed to, for example, provide the subscribers with a new service, inheritance of data from an old database to a new database is required as the software file is updated. 
     Various methods have been proposed as such switching system data inheritance methods. For example, Japanese Patent Laid-Open No. 1-292992 discloses a method of storing all subscriber information transferred from a database via common channel equipment in a database having a new structure. Japanese Patent Laid-Open No. 3-283894 discloses a method in which information indicating a specific type of conversion processing required for old data is registered in a table, and batch processing is performed. 
     According to the former method as a conventional switching system data inheritance method, information transferred via common channel equipment is inherited. For this reason, a separate conversion program or the like must be developed for management information, which is not generally transferred via the common channel equipment, to execute inheritance processing. According to the latter method, since information about conversion processing required for old data is registered in a table, information about conversion processing for each type of data must be registered depending on each database structure. 
     Limitations and restrictions regarding data types in data inheritance processing and changes in structure demand creation of new conversion programs or changes of programs, resulting in an increase in operation load. In addition, processing errors caused in creation/changes of conversion programs degrade the reliability of a new database. 
     SUMMARY OF THE INVENTION 
     It is an object of the present invention to provide a switching system data inheritance method and system which require no conversion programs and prevent degradation in the reliability of a database. 
     It is another object of the present invention to provide a switching system data inheritance method and system which prevent an increase in operation load. 
     In order to achieve the above objects, according to the present invention, there is provided a switching system data inheritance method of controlling hardware on the basis of a first database storing various management data such as subscriber information to inherit switching system data for various types of call connection processing, comprising the steps of creating change information indicating a change in structure from the first database to a second database which inherits data from the first database, and storing converted data in the second database by converting data constituting the first database into new data having a new structure and constituting the second database on the basis of the created change information. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a block diagram showing a switching system data inheritance system according to an embodiment of the present invention; 
     FIG. 2 is a view for explaining an old database schema in FIG. 1; 
     FIG. 3 is a view for explaining a new database schema in FIG. 1; and 
     FIG. 4 is a view for explaining an example of change schema information created by a schema change creating section in FIG.  1 . 
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENT 
     The present invention will be described next with reference to the accompanying drawings. 
     FIG. 1 shows a switching system data inheritance system according to an embodiment of the present invention. Referring to FIG. 1, reference numeral  1  denotes an old software file constituted by a old software program  2  for controlling various types of hardware in a switching system, an old database  3  (first database) consisting of various management data used for processing, and an old database schema  4  indicating the database structure of the old database  3 . 
     Reference numeral  5  denotes a new software file constituted by a new software program  6  for controlling various types of hardware in the switching system, a new database  7  (second database) consisting of various management data used for processing, and a new database schema  8  indicating the database structure of the new database  7 . 
     Reference numeral  11  denotes a database schema change creating section (database structure change creating section) comprising a new/old schema extracting section  12  for extracting pieces of new and old schema information from the new database schema  8  and the old database schema  4 , a new/old schema comparing section  13  for comparing the extracted pieces of new and old schema information with each other, and a schema change creating section  14  for creating new/old change schema information on the basis of this comparison result. 
     Reference numeral  15  denotes a database data converting section comprising an old database extracting section  16  for extracting old database information from the old database  3 , an old/new database converting section  17  for converting the old database into a new database on the basis of change schema information created by the database schema change creating section  11 , and a new database creating section  18  for creating a new database on the basis of the conversion result. 
     Data inheritance processing from the old database  3  to the new database  7  will be described, as an operation of the present invention, with reference to FIG.  1 . First of all, the new/old schema extracting section  12  of the database schema change creating section  11  extracts pieces of predetermined new and old schema information from the old database schema  4  of the old software file  1  and the new database schema  8  of the new software file  5 . 
     FIGS. 2 and 3 respectively show examples of the old database schema  4  and the new database schema  8  used in practice. The pieces of schema information of the old database schema  4  and the new database schema  8  are set, as pieces of information describing the respective database structures in detail, in units of tables constituting the old database  3  and the new database  7 . Reference numerals  21  and  31  denote pieces of management information;  22  and  32 , attribute values indicating field attributes constituting the tables; and  33 , a constituent factor added in the new database  7 . 
     The pieces of schema information of the old database schema  4  and the new database schema  8  are input to the new/old schema comparing section  13  to be compared with each other. In this case, the pieces of schema information associated with the same table are compared with each other, and the attribute values of the same field are compared with each other to extract a change in each attribute value. In addition, fields and attributes added/deleted between the old database schema  4  and the new database schema  8  are extracted as comparison results. 
     These comparison results are input to the schema change creating section  14 . In this case, pieces of change schema information between the old database schema  4  and the new database schema  8 , like those shown in FIG. 4, are created. 
     FIG. 4 shows an example of change schema information. Reference numeral  41  denotes management information indicating a corresponding table and the like; and  42 , change information. For example, “8” as an attribute “length range/maximum” in the old database schema  4  as indicated by reference numeral  22   a  in FIG. 2, is changed to “10” in the new database schema  8  as indicated by reference numeral  32   a  in FIG.  3 . With regards to this change, “UMAX8-10” denoted by reference numeral  42   a  as the change information  42  of “NAME1” is described in the change schema information in FIG.  4 . 
     Pieces of change schema information indicating changes between the old database schema  4  and the new database schema  8 , which are created by the schema change creating section  14 , are input to the old/new database converting section  17  of the database data converting section  15 . In this case, each data of the old database  3  which is extracted by the old database extracting section  16  is converted on the basis of change schema information. For example, the data length of the field of the above field name “NAME1” is changed from “8” to “10”, and addition/deletion of fields is performed. 
     These converted data are input to the new database creating section  18  and are reconstructed as a database to be stored in the new database  7  of the new software file  5 . With this operation, the new software program  6  controls various types of hardware of the switching system on the basis of the new database schema  8  and the constructed new database  7 . 
     In this manner, the database schema change creating section  11  creates change schema information from the old database schema  4  and the new database schema  8 , and the old database  3  is converted by the database data converting section  15  on the basis of the change schema information, thereby allowing the new database  7  to inherit the data. Any conversion programs based on database structures need not be created, and hence the operation load in data inheritance can be reduced. In addition, this system is free from data conversion errors caused by bugs accompanying creation/changes of programs as in a conventional system, and hence the reliability of a database can be maintained. 
     As has been described above, according to the present invention, this system includes a database structure change creating means for creating change information indicating a change in structure from the first database to the second database, and a database data converting means for converting each data constituting the first database into new data based on the second database on the basis of predetermined change information. With this arrangement, when the second database is to inherit each data from the first database, the database data converting means creates new data on the basis of change information created by the database structure change creating means, and the created data is stored in the second database. With this processing, any conversion programs depending on a database structure need not be created, and hence the operation load in data inheritance can be reduced. In addition, this system is free from data conversion errors caused by bugs accompanying creation/changes of programs as in a conventional system, and hence the reliability of a database can be maintained. 
     Furthermore, the database structure change creating means compares pieces of database schema information indicating the structures of the first and second databases to create change information on the basis of the comparison result. With this processing, any information indicating a difference between database structures need not be input, and accurate change information can be easily created.