JPH10214218A - System for managing database - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an object oriented data base management system in which the retrieval of an object can be attained at a high speed. SOLUTION: An object oriented DBMS 2 and a deduction DBMS 1 on a main storage are used. The attribute of an object is managed by the object oriented DBMS in the same way as a conventional manner, and link information between objects is managed as link information 5 stored on the main storage by reading link relation from a database 4 by the deduction DBMS 1 on the main storage. The link information 5 is managed by converting relation with another object applied by the attribute of the object into two augments.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] 1. Field of the Invention [0002] The present invention relates to an object-oriented database management system (DBMS), and more particularly to an object link information management system.

[0002]

2. Description of the Related Art An object-oriented database management system is used to manage the configuration of a substation in a power system monitoring and control system and the like. Parts configuration and the like can be naturally expressed.

FIG. 3 shows an example of managing substation facilities. It is assumed that three objects, a bank object, a circuit breaker object, and a transformer object, are stored in an object-oriented database and are linked to each other in a relation of “configuration” or “connection”.

At this time, for example, an operation of searching for a "transformer connected to a certain circuit breaker constituting a bank" is performed by first reading a "bank object" into a memory of a DBMS, and reading the value of the attribute "breaker". You can perform a search by loading the "Circuit Breaker Object" into the memory using and reading the "Transformer Object" into the memory using the value of the attribute "Transformer".

[0005]

In searching for an object by a conventional DBMS, an operation of reading an object into a memory and reading other objects into the memory one after another from the value of the attribute is performed by following a link. This means that links between objects are managed by the same mechanism as the attributes of objects.

[0006] In this object search using links, the more complicated the link relationship, the greater the amount of information read into the memory and the lower the search speed.

[0007] For example, in order to monitor and control a substation facility by expressing it in three-dimensional information, if the data to be stored in the object-oriented database is a spatial object having three-dimensional shape information, the object itself is a conventional object. In addition to being larger than simply expressing attribute values, the number of links to other objects is enormous.

When this three-dimensional object is searched by a conventional object-oriented DBMS, a large amount of information is read into the memory until the target object is reached, so that the cache memory is frequently replaced and the use efficiency of the cache memory deteriorates. At the same time, the search speed is reduced due to the overhead of the cache memory management.

It is an object of the present invention to provide an object-oriented database management system that speeds up object retrieval.

[0010]

According to the present invention, an object-oriented DBMS is used in combination with a deductive DBMS on a main memory, and the attributes of objects are set in the same manner as in the prior art.
S, and the link information between objects is managed by a deductive DBMS on the main memory, and is characterized by the following configuration.

[0011] An object-oriented database for storing the facilities of the system as objects and their attributes and link information between the objects, and processing of the objects in the database in response to an operation request from a client relating to the attributes of the object. A database management system, reads a link rule from a schema definition common to the database management system, extracts individual link information from a link relationship between objects of the database, and stores the link information in a data management area on a main storage; And a main storage deduction database management system that searches for and provides link information on the main storage in response to an operation request related to the link information via the database management system.

Further, the deduction database management system is characterized in that, as link information to be stored in a main memory, a relation to another object given by an attribute of an object is converted into two arguments and managed.

[0013]

FIG. 1 is a configuration diagram of a database system according to an embodiment of the present invention.

In order to obtain compatibility with the conventional method, the notation of the object is, for example, ODL (Obj) defined by the ODMG.
ectDescription (Language). Further, the main storage deductive DBMS 1 is operated on the back end of the object-oriented DBMS 2 and only when a search relating to link information is received from a client,
The object-oriented DBMS 2 requests the main storage deductive DBMS 1 for processing, receives the result, and returns it to the client.
The client is connected with the interface 3.

When the DBMS is started, first, the object-oriented DBMS 2 starts, and subsequently, the deductive DBMS 1, which is managed on the main storage, starts.

The deductive DBMS 1 reads the link rules between objects from the schema definition, extracts only the link information in the object-oriented database 4 via the object-oriented DBMS 2, and stores this as link information 5 in the main memory in a predicate format. . Data transfer is performed between the main storage and the database 4 via the cache memory 6.

FIG. 2 shows an example of the link information 5 corresponding to the link relation between the objects shown in FIG. 3. The link relations of "configuration" and "connection" and "bank object" and " A combination having an ID number of each facility such as a "transformer" and a "circuit breaker" is obtained.

In the above configuration, for example, the operation of searching for “the transformer connected to a certain circuit breaker constituting the bank” is performed by the deductive DBMS 1 referring to the link information 5 and the target bank object from its argument. Search for circuit breakers and transformers based on the ID of

More specifically, a search is made for two argument predicates "composition" that take a bank object ID type as the first argument and a breaker object ID type as the second argument, and find the value of the first argument as a target. Of the bank object to be selected. Next, the circuit breaker object ID is used as the first argument.
A predicate "connection" that takes the transformer object ID type as the type and the second argument is searched, and the one having the same value as the second argument of the "configuration" selected earlier is selected from among them.

The ID of the target object in this selection
Is obtained, a document managed by the object-oriented DBMS 2 is read as needed for the corresponding object, and the client can refer to the document.

[0021]

As described above, according to the present invention, the object-oriented DBMS is used in combination with the deductive DBMS on the main memory, the attributes of the objects are managed by the object-oriented DBMS as in the past, and the link information between the objects is maintained. Since the management is performed by the deductive DBMS on the main memory, the following effects are obtained.

(1) The main memory deductive DBMS for managing link information between objects only needs to handle small fixed-length data called an object ID, and is suitable for managing data on the main memory. You can search.

(2) By predetermining the types of arguments of the predicate, the narrowing down of objects can be performed at high speed.

(3) The deductive DBMS uses object-oriented D
Since it operates on the BMS back end, it can be handled from the client in the same way as the management by the conventional object-oriented DBMS.

[Brief description of the drawings]

FIG. 1 is a configuration diagram of a database system showing an embodiment of the present invention.

FIG. 2 is an example of link information in the embodiment.

FIG. 3 is an example of a link relationship between objects in an object-oriented database.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Deductive DBMS 2 ... Object-oriented DBMS 3 ... Interface 4 ... Object-oriented database 5 ... Link information 6 ... Cache memory

Claims (2)

[Claims] 1. An object-oriented database for storing equipment of a system as objects and their attributes and link information between the objects, and an object request from a client relating to the attributes of the object, the object of which is stored in the database. A database management system to be processed; a link rule read from a schema definition common to the database management system; individual link information extracted from a link relationship between objects of the database; and stored in a data management area on a main storage. And a main storage deduction database management system for searching and providing link information on the main storage in response to an operation request related to the link information via the database management system. 2. The deduction database management system,
2. The database management system according to claim 1, wherein the link information stored in the main storage is managed by converting the relation to another object given by the attribute of the object into two arguments.