JPH04323742A - Distributed data base system - Google Patents

Abstract

PURPOSE:To enable a user to perform the data base processing without paying his attention to the attribute of the result value at the time of access request. CONSTITUTION:In the distributed data base system where the data base processing language for data definition, operation, and control of a data base is used to perform the data base processing in response to the access request of the user, a client and a server are provided with string attribute management means 3 and 7 respectively, and the server is provided with a string attribute management table 8, and the string attribute management means 7 obtains the attribute of the result value based on the string attribute management table 8 and returns it to the client together with the result value. Otherwise, string attribute information held in the string attribute management means 3 of the client is obtained or the string attribute management means 7 of the server is inquired about string attribute information, and the attribute of the result value is transmitted to the server together with the data base processing language, the argument value, and the attribute of the argument value.

Description

[Detailed description of the invention]

0001

FIELD OF INDUSTRIAL APPLICATION The present invention is utilized for managing distributed databases. The present invention relates to a distributed database system that allows users to perform database processing without being aware of attributes of result values when making access requests.

0002

[Background Art] Conventionally, this type of column attribute management requires users to be aware of the attributes of each column in the database they are trying to access, and to specify the attributes defined in the database as the attributes of the result value. , the distributed database control means of the client that has received the access request to the database transfers the database processing language, the argument value, and the attributes of the argument value as well as the attributes of the result value specified by the user to the server, and the server that received this access request performed processing on the database based on the attributes of the argument value and result value specified by the user, and sent only the result value to the client.

0003

[Problem to be Solved by the Invention] In conventional column attribute management, as mentioned above, it is necessary for the client side to transfer the attributes of the result value to the server. It was necessary to manage the results and specify the attributes of the result values to the client's distributed database control means.

[0004] The present invention is intended to solve such problems, and an object thereof is to provide a system that eliminates the need for a user to be aware of the attributes of a result value when making an access request.

[0005]

[Means for Solving the Problems] The present invention provides a system in which a plurality of clients and a server are connected via a communication line, and when the client receives an access request from a user, the access request is transmitted in a database processing language. , argument value,
and distributed database control means for converting argument values into attributes and issuing a database processing request to the server, and communication control means for transferring an access request to the server via the communication line, A database that is the target of an access request, a communication control means that receives a database processing request from the client, a distributed database control means that performs database processing according to the access request received by the communication control means, and a database that is the target of the access request. In a distributed database system comprising a database access means for accessing data, the server is provided with a column attribute management table that holds attributes of each column of the database, and the distributed database control means of the client stores attributes of result values. When omitted, the present invention is characterized by comprising a column attribute management means for determining a data attribute corresponding to a result value by referring to the column attribute management table.

[0006] The client is provided with a column attribute management means that holds the attributes of each column of the database in advance and obtains the attributes of the result value requested by the user; , the column attribute management means of the server includes means for inquiring the column attribute management means of the server about the column attribute and returning the attribute of the result value to the distributed database control means, when the column attribute management means of the server does not hold the column attribute of the server. It is desirable to include means for obtaining the attributes of each column in the database in response to a column attribute acquisition request from the column attribute management means of the client.

[0007]

[Operation] When performing database processing in response to requests from users for data definition, manipulation, and control for a database that stores data scattered across multiple clients and servers connected to each other via communication lines. On the client side, if the attribute of the result value is not specified in the user's database processing request, the distributed database control means first performs database processing on the scattered databases, and then the column attribute management means The attribute information of each column is retained by querying it in advance, and the attribute of the result value can be obtained before making an access request to the server, and the database access request is forwarded to multiple servers via a communication line. .

On the server side, a database processing request transferred from a client is received, a distributed database control means performs database processing in response to the database access request, and a column attribute management means maintains the attributes of each column of the database. The column attributes of the database are provided to the distributed database control means by referring to the column attribute management table, and the target data is accessed from the database.

[0009] This eliminates the need for the user to be aware of the attributes of the result value when making an access request.

0010

Embodiments Next, embodiments of the present invention will be described with reference to the drawings. Figure 1 is a block diagram showing the configuration of an embodiment of the present invention, Figure 2
FIG. 2 is a diagram showing the structure of a column attribute management table in an embodiment of the present invention.

In the embodiment of the present invention, when a plurality of clients A and a server B are connected via a communication line, and client A receives an access request from user 1, the access request is processed using a database processing language. Distributed database control means 2 that converts argument values into attributes of argument values and requests database processing to server B; and server B.
A communication control means 4 that transfers an access request to the server B via a communication line, a database 10 to which the access request is made, a communication control means 5 that receives a database processing request from the client A, and a communication control means 5 that receives a database processing request from the client A. The present invention has a distributed database control means 6 that performs database processing according to an access request received by the communication control means 5, and a database access means 9 that accesses target data from the database 10. A column attribute management table 8 is provided to hold the attributes of each column of the database 10, and when the distributed database control means 2 of client A omits the attribute of the result value, the data attribute corresponding to the result value is managed in the column attribute management table 8. A column attribute management means 7 is provided for determining column attributes with reference to Table 8.

[0012] The client A is also equipped with a column attribute management means 7 that holds the attributes of each column in the database 10 in advance and obtains the attributes of the result value requested by the user. , includes means for inquiring column attributes from the column attribute management means 7 of the server and returning the attributes of the resultant value to the distributed database control means 6 when the attributes of each column of the database 10 are not held;
The column attribute management means 7 includes means for obtaining the attributes of each column in the database 10 in response to a column attribute acquisition request from the column attribute management means 3 of the client A.

Next, the operation of the embodiment of the present invention constructed as described above will be explained. FIG. 3 is a flowchart showing the operation flow of the column attribute management means of the server in the embodiment of the present invention.

[0014] The column names corresponding to the database processing result values requested by user 1 are "COL2" and "COL4".
In this case, the distributed database control means 6 of server B
receives a request for access to the database 10 from the user 1 from the communication control means 5, and determines whether the user 1 has specified an attribute of the result value (S1). If the user 1 specifies the attribute of the result value, a database processing request is requested to the database access means 9 using the specified attribute of the result value.

[0015] If the user 1 does not specify the attribute of the result value, the distributed database control means 6 uses the column attribute management means 7
call. The column attribute management means 7 performs a process of associating the result value requested by the user with the column name of the database (S
2) Obtain "COL2" and "COL4", perform processing to search for column names "COL2" and "COL4" among the attributes registered in the column attribute management table 8 (S3), and check the result values. Data type “NUMERIC”, precision “4” as attributes,
Scale “2”, data type “INTEGER”, precision “4”
” and provides it to the distributed database control means 6. The distributed database control means 6 performs database processing based on the attributes of the obtained result value, and transmits the result value and the attributes of the result value to the communication control means 5 to the client. request that it be sent to.

In this manner, the column attribute management means 7 performs the above operations whenever necessary in response to a request from the distributed database control means 6 to acquire attributes of result values.

FIG. 4 is a flowchart showing the operation flow of the column attribute management means of the client in the embodiment of the present invention.

[0018] The column names corresponding to the database processing result values requested by user 1 are "COL2" and "COL4".
In this case, the distributed database control means 2 of the client A receives the user 1's request for access to the database 10, and determines whether the user 1 has specified an attribute of the result value (S5). If the user 1 has specified the attribute of the result value, a process is performed to request the communication control means 4 to perform database processing using the attribute of the specified result value (S
10).

[0019] If the user 1 does not specify the attribute of the result value, the distributed database control means 2 specifies the column attribute management means 3.
call. The column attribute management means 3 determines whether column attribute information of the database 10 is held (S6),
If column attribute information is not held, column attribute management means 7
Inquiry processing for column attributes is performed on the column attributes (S7) to obtain attribute information.

Next, a process is performed to associate the result value requested by the user with the column name of the database (S8).
L2” and “COL4” are acquired, and among the attribute information held in the column attribute management means 3, the column names are “COL2” and “CO
L4" (S9), data type "NUMERIC", precision "4", scale "2", data type "INTEGER", precision "4" are obtained as attributes of the result value, and the distributed database is The information is provided to the control means 2.

The distributed database control means 2 performs a process of requesting the communication control means 4 to transmit the attribute of the obtained result value to the server B together with the database processing language, the argument value, and the attribute of the argument value (S10).

In this way, the column attribute management means 3 performs the above operations whenever necessary in response to a request from the distributed database control means 2 to acquire attributes of a result value.

[0023]

As explained above, according to the present invention, in a distributed database system that performs database processing in response to user access requests, a column attribute management means that holds attribute information of each column of a database and a column attribute Providing a management table has the effect of eliminating the need for users to be aware of the attributes of result values when making access requests.

[Brief explanation of drawings]

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

FIG. 2 is a diagram showing the structure of a column attribute management table in the embodiment of the present invention.

FIG. 3 is a flowchart showing the operation flow of the column attribute management means of the server in the embodiment of the present invention.

FIG. 4 is a flowchart showing the operation flow of the column attribute management means of the client in the embodiment of the present invention.

[Explanation of symbols]

1 User 2, 6 Distributed database control means 3, 7 Column attribute management means 4, 5 Communication control means 8 Column attribute management table 9 Database access means 10 Database 11 Communication line A Client B Server

Claims (3)

[Claims] Claim 1: A plurality of clients and a server are connected via a communication line, and when the client receives an access request from a user, the access request is processed using a database processing language, an argument value, and an argument value. distributed database control means that converts the attributes into database processing requests to the server; and communication control means that transfers the access request to the server via the communication line; a database, a communication control means that receives a database processing request from the client, a distributed database control means that performs database processing in accordance with the access request received by the communication control means, and a distributed database control means that accesses target data from the database. In a distributed database system comprising a database access means, the server is provided with a column attribute management table that holds attributes of each column of the database, and when the distributed database control means of the client omits an attribute of a result value. . A distributed database system comprising column attribute management means for determining a data attribute corresponding to a result value by referring to the column attribute management table. 2. The distributed database system according to claim 1, wherein the client comprises a column attribute management means that holds the attributes of each column of the database in advance and obtains the attributes of the result value requested by the user. 3. When the column attribute management means of the client does not hold the attributes of each column of the database, the column attribute management means of the server inquires about the column attributes, and the attribute of the result value is stored in the distributed database. 2. The column attribute management means of the server includes means for requesting the attributes of each column of the database in response to a column attribute acquisition request from the column attribute management means of the client. Distributed database system.