JP2748986B2 - Buffer management method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a database system, and more particularly to a buffer management system for efficiently querying a database.

[0002]

2. Description of the Related Art A database is a system capable of completely and economically storing, handling, and retrieving data, and its functions have become more efficient with the development of computers.

[0003] In recent years, the application fields of databases have expanded from data processing in the business field to engineering fields such as design. Such advanced applications not only search from a collection of data of the same type in a database,
There is a demand for efficient access to different related data. However, in the conventional database buffer management method, basically the same data is collectively stored and the collected information is read out to the buffer when necessary.

[0004]

The buffer management in the database as described above is suitable for collective search and has a feature that the search can be performed efficiently. However, it is not suitable for accessing data of different types, and has a problem that the user has to copy and use the data in each program area. In addition, these users have to write extra programs, and the same data can be copied for each program. Had.

SUMMARY OF THE INVENTION An object of the present invention is to provide a buffer management system for easily and efficiently accessing not only data of the same type but also data of a different type.

[0006]

FIG. 1 is a block diagram showing the principle of the present invention. According to the present invention, a database stored in the storage means 1 is stored in a first buffer 2 using a page buffer.
In a database system that manages and accesses data units of the same type.

[0007] The second buffer 3 is the first buffer 2
Manage related data in units other than those managed in. The controller 4 receives a database inquiry request, selects and evaluates the first buffer 2 or the second buffer 3 in response to the request, and outputs a result of the evaluation.

[0008]

When a database inquiry request is added, the control unit 4 selects and evaluates the first buffer 2 or the second buffer 3 in response to the input request. The first buffer 2 stores data managed in the same type of data unit. When the requested data is not the same type of data, related data other than the management unit is stored in the second buffer 3. The managed second data may be stored in the first buffer 2, for example. Further, the first buffer 2 and the second buffer 3 may be separately selected and evaluated, and the result of the evaluation may be stored.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail with reference to the drawings.
FIG. 2 is a block diagram of an embodiment of the present invention. The query evaluation unit 11 receives a database query request from a user, and in response to the request, the query evaluation unit 11 calls the database 14 into the page buffer 13 and collectively manages a part of the same type of data in the database 14. . On the other hand, when the request is not data to be stored in the page buffer 13 managed collectively, related data is stored in the object buffer 12 and related data of a different type is obtained.

FIG. 3 is a flowchart of a process in response to a request in the inquiry processing unit 11. When a request is added, it is first determined whether or not database data corresponding to the request exists in the object buffer 12 (S
1) If it does not exist (N), the process by the page buffer (S2) is performed and the target data in the database 14 is stored in the page buffer 13. Then, data for the object buffer obtained by the processing (S2) by the page buffer 13 is created. Processing (S2)
(S1) to determine whether the object exists after or in the object
When it is determined that the object exists in the object (Y), the process (S3) using the object buffer is executed, and the process for the request ends.

The above-mentioned database will be described in detail. As shown in FIG. 4, a piston, a connecting rod, a crank, and a mass are associated with an engine. Data is stored. When the data shown in FIG. 4 is stored in the database 14 and processing in the page buffer is necessary, the data in FIG. 4 is read and stored in the page buffer. And when the access is related to different types of data, the fifth
As shown in Fig. (A), in response to a query to "find the mass of the engine as long as there is data", the data of the engine, piston, connecting rod, and crank are moved from the database to the page buffer. Then it sends the relevant data to the object buffer. Note that this is the case for accessing different types of related data.

On the other hand, in the case of data search of the same type, for example, when a search is performed for an engine name with an engine mass of 15,000 or less as shown in FIG. It is done on a close object buffer. At this time, the page buffer and the object buffer may be different. In the first method, the data of the engine is moved from the object buffer to the page buffer, and then the query is evaluated on the page buffer. In the second method, the same query is separately evaluated on the object buffer and the page buffer, and the results are merged.

FIG. 6 (a) is a diagram showing the configuration of a database of pistons and connecting rods for the aforementioned engine. When such a database exists, the data structure in the page buffer in response to the inquiry request is the same as that in FIG. 6 (a) as shown in FIG. 6 (b). That is, the database 14
Is stored on a disk, for example, and the data in the page buffer is stored on a memory. When these are represented by the data structure in the object buffer, the engine 1 is converted into the piston 1, the connecting rod 1, and the engine 3 is converted into the piston 3, the connecting rod 3 and the pointer as shown in FIG. 6 (c). The processing for the database inquiry request will be further described in detail with reference to FIGS.

FIG. 7 shows a case of access to heterogeneous data. When a request occurs, it is determined whether or not the requested data exists in the object buffer (S11). It is determined whether there is (S12). If there is no data in the page buffer, the data is copied from the database to the page buffer (S13). When it is determined (in step S12) that there is data in the page buffer, or when processing (S12) is performed.
When the data is copied from the database to the page buffer according to 13), the data is copied from the page buffer to the object buffer (S14), and the data in the object buffer is returned as a result (S15). When it is determined (S11) that data exists in the object buffer (YES), the data in the object buffer is returned (S15).

On the other hand, for an inquiry for the same type of data, there are two inquiry result outputs as shown in FIGS. 8 (a) and 8 (b). In the first method, it is determined whether or not there is related data on the object buffer (S21). At some time (a certain time), data is copied from the object buffer to the page buffer (S22).
The query is evaluated on the page buffer (S23),
Outputs the query result. When it is not determined (S21) whether there is related data in the object buffer (S21), the query (S23) is similarly evaluated on the page buffer.

In the second method, it is determined whether there is related data on the object buffer in response to the request (S31), and at a certain time (a certain time), an inquiry is separately made on both the object buffer and the page buffer. Are evaluated and the results are integrated (S32). The result is output as the result of the query. When it is determined in the determination (S31) that there is no relevant data on the object buffer (none), the query is evaluated on the page buffer (S33) and output as a query result. As described above, it is possible to efficiently evaluate accesses to different types of data and accesses to the same data.

[0017]

As described above, according to the present invention, it is possible to efficiently process accesses to data of different types,
Further, conventional data retrieval of the same type can be performed, and data processing accompanying advanced application of the database can be efficiently processed.

[Brief description of the drawings]

FIG. 1 is a principle block diagram of the present invention.

FIG. 2 is a configuration diagram of an embodiment of the present invention.

FIG. 3 is a processing flowchart for a request.

FIG. 4 is a definition table of a database.

FIG. 5A is a chart of an example of an inquiry (access of successive different types of data), and FIG. 5B is a chart of an example of an inquiry (search for data of the same type).

6A is a diagram showing the configuration of a database, FIG. 6B is a diagram showing the data configuration in a page buffer, and FIG. 6C is a diagram showing the data configuration in an object buffer.

FIG. 7 is a processing flowchart for heterogeneous data.

FIGS. 8A and 8B are processing flowcharts for inquiring of the same type data.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Storage means 2 1st buffer 3 2nd buffer 4 Control diagram

Claims (4)

(57) [Claims] In a database system in which a database stored in a storage means (1) is managed and accessed by a first buffer (2) having a page buffer in the same type of data unit, the database is managed by the first buffer. A second buffer (3) for managing related data in units other than the unit to be executed and a request for querying the database are added, and the request is selected and evaluated by selecting the first buffer or the second buffer. A buffer (4) for outputting a result of the evaluation. 2. The method according to claim 1, wherein the selection is performed after managing related data in units other than the management unit in the second buffer, and storing the management result in the first buffer. Item 2. The buffer management method according to Item 1. 3. The buffer management method according to claim 2, wherein said control means performs an evaluation after said selection is made. 4. The method according to claim 1, wherein the control means selects and evaluates the first buffer and the second buffer separately for the same inquiry, and merges the evaluation results. The buffer management method described.