JPH0749880A - Data base access request device - Google Patents

Abstract

PURPOSE:To sends certain access requests to plural data bases that are connected through a communication line and to efficiently obtain process results at a high speed. CONSTITUTION:A request analysis part 23 analyzes a data base access procedure 10 in advance and obtain access request statements by the data base. Further, it is judged whether or not there is such dependency relation that they utilize retrieval results mutually and when not, the access request statements are sent to respective data base processors 4 by a broadcasting communication. Consequently, the time required for the transmitting and receiving procedure of the access requests is shortened and the retrieval time of the data bases for simultaneous parallel processing is also shortened. Access request statement in dependency relation are only processed in order as usual.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a database access requesting device for requesting access to a plurality of databases connected via a communication line and obtaining a certain processing result.

[0002]

2. Description of the Related Art In various fields such as science and technology, commerce, personnel management, finance, etc., information processing devices are widely used to search databases. These databases do not always exist centrally in one place, but are arranged in various places via communication lines. Users often obtain predetermined results based on information obtained from multiple databases.

FIG. 2 shows a block diagram of such a conventional database search device. This device accesses a database 5 connected by a database access requesting device 1 via a communication line 3. The database access requesting device 1 is connected with a pre-processing unit 2 for inputting an access request. Further, in the database access request device 1, the access control unit 6 and the storage unit 7 are included.
Is provided. The communication line 3 is connected to the database 5 via the database processing device 4.

The database 5 is composed of a mass storage device such as a magnetic disk device, and the information stored therein is searched by the database processing device 4 and sent to the database access requesting device 1 via the communication line 3. Has become. In order to use the database access requesting device 1 to obtain necessary information from the database, the operator must input a certain access procedure. In order to facilitate the input of such an operator's access procedure, there is a simple language called SQL. The preprocessing unit 2 is a unit for converting such a simple language into a language that can be interpreted by the database access requesting device 1.

FIG. 3 shows an operation explanatory diagram of the SQL preprocessing section. The pre-processing unit 2 receives the SQL program 11 and processes it.
Two are provided. The SQL program 11 is a simple language for searching a database.
Like BASIC and COBOL, it belongs to a high-level language.
The SQL preprocessing device 12 converts the SQL program 11 into a program in a so-called assembler format and sends it to the database access request device 1.
This is interpreted by the database access requesting device 1 and stored in the storage unit 7 as a database access procedure 10.

Specifically, the database access procedure 10 has a content such that a certain file is searched within a predetermined range based on a certain key and the obtained data is sent back. Such a database access procedure 10 is sequentially read by the access control unit 6 and sent as an access request statement 8 to the database processing device 4.
Upon receipt of this, the database processing device 4 receives the database 5
And the necessary processing result 9 is sent back to the database access requesting device 1 via the communication line 3.

[0007]

By the way, the above-mentioned conventional database retrieval apparatus has the following problems to be solved. FIG. 4 shows a conventional search processing sequence. The procedure by which the conventional database access requesting device 1 makes various access requests to a plurality of databases and obtains the processing results is as shown in this sequence.

That is, first, the database access procedure 10 shown in FIG. 2 is processed in the order of databases for which access requests should be made. That is, in step S1 of FIG.
First, a corresponding access request is made to the database processing device 4-1. Then, this database processing device 4-
The processing result from 1 is received in step S2.
Next, the database access procedure prepared for another database search is read, and an access request is issued to another database processing device 4-2 in step S3. Then, in step S4, the database processing device 4-2 transmits the processing result to the database access requesting device 1. Finally, the database access requesting device 1 makes an access request to the remaining database processing device 4-3 in step S5, and receives the processing result in step S6.

However, in order to execute the above-mentioned processing, the database access requesting apparatus 1 needs a certain communication procedure for connecting to the database processing apparatus 4 via the communication line 3 shown in FIG. Therefore, in order for the database access requesting device 1 to obtain a processing result from each of the database processing devices 4-1 to 4-3 shown in FIG.
A certain process for connecting and disconnecting such a communication line is required. However, the database processing device 4-1
.. 4-3, even if compared with the time for searching each database, take steps for the database access requesting device 1 to connect to each database processing device 4-1 to 4-3 via the communication line. The time can be so long that it cannot be ignored.

Therefore, in order to obtain all the processing results and proceed to the next information analysis work, the database access requesting apparatus 1 requires a very long processing time, and its processing efficiency becomes a problem. In particular, when the database access requesting device 1 and the database processing devices 4-1 to 4-3 are connected by a low-speed communication line, there is a problem that the performance is significantly deteriorated due to communication delay. . Therefore, there has been a demand for improved efficiency in executing complicated access requests for a plurality of databases.

The present invention has been made by paying attention to the above points, and when a constant access request is made to a plurality of databases connected via a communication line, the processing is performed more efficiently and at a high speed as a whole. It is an object of the present invention to provide a database access requesting device that can obtain a result.

[0012]

A database access request device of the present invention is a device for requesting access to a plurality of databases connected via a communication line and obtaining a processing result. And the stored database access procedure are analyzed to distinguish the access request statements for each database and to determine whether or not each access request statement has a dependency relationship in which the search results are used with each other. It is characterized by including a request analysis unit and an access control unit that sends access request statements having no dependency relationship to each database at the same time to perform a parallel search process.

[0013]

In this device, the request analysis section obtains an access request statement for each database by analyzing the database access procedure in advance. Further, it is judged whether or not they have a dependency relationship in which the search results are used with each other, and if there is no dependency relationship, the access request sentence is sent to each database processing device by broadcast communication. This saves the time required to send and receive data and access requests, and saves database search time due to concurrent processing. Access request statements having a dependency relationship may be processed in the same manner as in the past.

[0014]

The present invention will be described in detail below with reference to the embodiments shown in the drawings. FIG. 1 is a block diagram showing an embodiment of a database access request device of the present invention. This device is configured to access a plurality of databases 5 connected via a communication line 3 by a database access requesting device 20. Here, three types of databases 5 are displayed, and the database processing device 4 is configured to search each database 5.

The database access request device 20 includes
An access control unit 21, a storage unit 22, and a request analysis unit 23 are provided. Further, a preprocessing unit 2 is provided to send the database access procedure 10 to the database access requesting device 20. The configuration and operation of the pre-process section 2 are the same as those of the conventional apparatus already described with reference to FIG.

Here, the dependency of the access request sentence will be described. FIG. 5 is an explanatory diagram of the dependency relationship of access request statements. As described above, the database access procedure 10 sent to the database access requesting device 20 determines, for example, what file is opened for each database, what kind of key is used to search what range, and the like. Contains instructions. When such a search is performed on a plurality of databases, an access request statement for each database is included. Here, for example, access request statements 10A, 10B, 10C
Configure the database access procedure 10.

In this case, each access request statement 10A, 1
In some cases, the processing results obtained by 0B and 10C are sent as they are to another information processing apparatus and used. However, for example, as shown by a broken line 15 in this figure, the access request statement 10C may use the search result obtained by the access request statement 10B. If there is such a dependency, for example, if the access request statement 10C is executed first and then the access request statement 10B is executed, an error will occur in the result. In the present invention, the presence or absence of such a dependency relationship is determined, and when there is no dependency relationship in the result at all, transmission of the access request statement is performed as parallel processing by broadcast communication to speed up the processing.

FIG. 6 shows a search processing sequence by the apparatus of the present invention. The operation of the apparatus of the present invention will be described in order with reference to this sequence chart. In FIG. 1, the preprocessing unit 2 sends a predetermined database access procedure 10 to the database access requesting device 20.
When the database access procedure 10 is stored in the storage unit 22, the request analysis unit 23 analyzes the database access procedure 10. Then, as shown in FIG. 5, it is divided into access request statements for different databases. Next, investigate these dependencies. First, as a first example, consider a case where the access request statements have no dependency at all. In this case, the access request is sent to the database processing device 4-1 as shown in step S1 of FIG.
Further, the access request is sent to the database processing device 4-2 in step S2, and the access request is sent to the database processing device 4-3 in step S3. These access requests are carried out by broadcasting at substantially the same time.

Type of communication line and database processing device 4
Such access requests arrive at the database processing devices 4-1, 4-2, and 4-3 at different times depending on the distances from -1 to 4-3. After the arrival of the access request, these database processing devices execute a database search to obtain a certain processing result. The database access requesting device 20 outputs the processing results of these database processing devices 4-1 to 4-3 to steps S4 and S5.
It is received in S6.

Here, as is apparent by comparing FIG. 6 with FIG. 4 which illustrates the operation of the conventional apparatus, in the apparatus of the present invention, the database access requesting apparatus 20 makes an access request to the database processing apparatus 4-3. And other processing results are received before the processing results are received. In other words, it takes the longest time to communicate, it takes a long time to search the database, and the total reception of processing results is slow. It is possible to receive all processing results by setting the database request to the database processing device as the maximum time. Become. Therefore, it is preferable to issue the access request first to the database that requires the longest time to complete the access response.

By the way, there is a case where a certain dependency exists in the above access request statement. However, it is rare that all access request statements have a dependency relationship with each other. For example, an access request is made to the database processing device 4-1, and the processing result is an access to the database processing device 4-2 or the database processing device 4-3. There are also cases where it affects requirements. In such a case, as shown in step S7 of FIG. 6, first, an access request is made only to the database processing device 4-1.
In step S8, the processing result is received. Then, in steps S9 and S10,
Access requests are made all at once to the database processing devices 4-2 and 4-3 by broadcast communication. Then, after that, when any one of the database processing devices which is later in receiving the processing request receives the processing request, all the processing is completed.

The disassembly, assembly, parallelization, format conversion and the like of the database access procedure are executed by the request analysis unit 23 of the database access request device 20 shown in FIG. 1 by a predetermined program. Further, the request analysis unit 23 generates information about whether or not the broadcast communication is required, sends it to the access control unit 21, and connects to the communication line 3 by the well-known broadcast communication procedure of a facsimile machine or the like. And so on.

The present invention is not limited to the above embodiments. The preprocessing unit 2, the storage unit 22, the request analysis unit 23, the access control unit 21 and the like in the above embodiment may be replaced with various kinds of hardware and software having the same function, and these devices are integrated into a computer. It can be configured with software. Further, it goes without saying that the type of database, the type of communication line, the number, etc. may be freely changed. The timings for simultaneously making access requests to a large number of databases may be exactly the same in time, or may be such that access requests are made one after another at very short intervals. In effect, another access request is issued before the processing result is received for an access request, and the transmission of the access request to each database processing device and the database search process of each database processing device are performed in parallel. It only needs to be processed.

[0024]

According to the database access request apparatus of the present invention described above, the request analysis unit analyzes the access procedure for making access requests to a plurality of databases, and distinguishes the access request statement for each database.
Judging whether or not these request statements have a dependency relationship that uses the search result with each other, and when there is no dependency relationship, the access request statement is sent to each database at the same time, and the search is processed in parallel. It becomes possible to access a large number of databases in a sufficiently short time, as compared with the case where the database access procedure previously generated by the preprocessing unit is sequentially performed as in the conventional case.

[Brief description of drawings]

FIG. 1 is a block diagram showing an embodiment of a database access request device of the present invention.

FIG. 2 is a block diagram showing a conventional database search device.

FIG. 3 is an operation explanatory diagram of an SQL preprocessing unit.

FIG. 4 is a search processing sequence of a conventional device.

FIG. 5 is an explanatory diagram of a dependency relationship of access request statements.

FIG. 6 is a search processing sequence by the device of the present invention.

[Explanation of symbols]

 2 pre-processing unit 3 communication line 4 database processing device 5 database 10 database access procedure 20 database access request device 21 access control unit 22 storage unit 23 request analysis unit

Claims (1)

[Claims] 1. A storage unit for requesting access to a plurality of databases connected via a communication line to obtain a processing result, the storage unit storing an input database access procedure, and the stored database access procedure. And the access request statements for each database are distinguished, and the request analysis section that determines whether each access request statement has a dependency relationship that uses the search result with each other, and an access request statement that does not have a dependency relationship A database access requesting device comprising: an access control unit that sends the data to each database at the same time and processes the search in parallel.