JP2000259561A - System and method for data base access control - Google Patents

Abstract

PROBLEM TO BE SOLVED: To attain efficient multi-thread data base access by managing and controlling the data base access from respective threads in access to a data base. SOLUTION: A smaller number between a maximum connection number determined by a data base dedicated driver 12 and a maximum connection number determined by the specifications of an entire system is set as the maximum connection number of data base access. Then, a DB access manager 15 unitarily manages and controls the data base access from respective threads in data base access processing and controls the number of data base access processing threads to be requested at the same time smaller than the above set maximum connection number.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a database access control system and method, and more particularly to a database access control system and method capable of efficient multi-thread database access.

[0002]

2. Description of the Related Art In general, a large amount of data is stored in a database and used by many users at the same time. Therefore, in operating a database system, a system is used to support users and application programs. The side needs to provide a lot of functionality. For this reason, a database management system (DBMS) is used to manage the database in an integrated manner mainly when operating the database. This database management system has at least a basic function for making an application program access a database.

FIG. 3 shows a prior art database access. Here, reference numeral 10 denotes a database (DB), and the database-dedicated driver 12 is a dedicated driver for controlling access to the database 10. The database driver manager 14 manages the database-specific driver 12 and
The connection to is made.

A database API (application programming interface) 16 is a connection interface between a database access process (thread) 18 and a database driver manager 14.
As a result, it is possible to connect the program to the database server, to assemble the SQL statement and execute it on the database server, to retrieve the result processed by the database server, and to retrieve information on the database, information on the processing result, and the like. Become.

[0005] However, conventionally, the database has not managed access processing to the database, and thus has the following problems.

If an attempt is made to connect beyond the maximum number of connections determined by the driver, the database cannot be connected and an error occurs.

If the driver is not multi-thread compatible,
When each thread accesses the database at the same time when a single thread can cope, deadlock occurs.

[0008] The number of connections to the database cannot be limited,
Accepting all requests reduces overall system performance. In addition, competition with the database is likely to occur.

[0009]

SUMMARY OF THE INVENTION Therefore, the present invention solves such a problem, and manages and controls database access from each thread in accessing a database, thereby achieving efficient database access by multi-threading. It is intended to make it possible.

[0010]

SUMMARY OF THE INVENTION A database access control system and method of the present invention comprises a database 10;
A database driver 12 for controlling access to the database 10, a database driver manager 14 for managing the database driver 12 and connecting to the database 10, a database access process 18 and a database driver manager 14. Database A which is the connection interface of
A PI (application programming interface) 16 is provided to control access to the database. The smaller of the maximum number of connections determined by the database dedicated driver 12 and the maximum number of connections determined by the specifications of the entire system is set as the maximum number of database access connections. Then, the DB access management 15 centrally manages and controls database access from each thread of the database access processing, and manages the number of simultaneously required database access processing threads to be equal to or less than the set maximum number of connections. .

[0011]

FIG. 1 is a diagram for illustrating a database access configuration according to the present invention. Here, reference numeral 10 denotes a database (DB), and the database-dedicated driver 12 is a dedicated driver for controlling access to the database 10. The database driver manager 14 manages the dedicated database driver 12 and connects to the database 10.

A database API (application programming interface) 16 is a connection interface between a database access process (thread) 18 and a database driver manager 14.
As a result, it is possible to connect a program to a database server, assemble an SQL statement and execute it on the database server, retrieve a result processed by the database server, and retrieve information on the database and information on the processing result. Become.

The database access management 15 manages and controls database access from each thread of the database access processing 18, and there may be a plurality of Ds.
The B access processing 18 is centrally managed by the DB access management 15. The number of database access processing threads requested simultaneously for the database was set to the smaller of the maximum number of connections determined by the database dedicated driver 12 and the maximum number of connections determined by the specifications of the entire system. It is managed and controlled below the maximum number of connections. Requests for processing exceeding the maximum number of connections are queue-managed and waited until the number of requests falls below a predetermined number.

The details of the database access management 15 will be described in further detail with reference to a flowchart of FIG. 2, the DB access management on the left side and the DB access processing on the right side correspond to the DB access management 15 and the DB access processing 18 in FIG. 1, respectively.

When the DB access management flow starts,
In step ST1, the maximum connection number of the driver from the DB dedicated driver 12 to the database 10 is obtained. In step ST2, the file is a file for managing the server environment. For example, according to the specifications of the entire system, the maximum number of connections to the database 10 can be obtained from a "server environment file" that defines the maximum number of simultaneous connections to the database. To get. In step ST3, step ST
The maximum number of connections to be managed is set based on the maximum number of connections to the database 10 obtained from the DB dedicated driver 12 in step 1 and the maximum number of connections to the database 10 obtained from the server environment file in step ST2. That is, the smaller maximum number of connections is set.

At step ST4, if there is a request from the DB access processing thread side for data reference (acquisition), update, deletion, etc., it is registered in the DB access queue. In step ST5, it is checked whether or not the number of database accesses registered in the queue is less than the maximum number of connections set in step ST3. Return to step ST5, if not, step ST
In step 7, the number of connections is counted up. That is, DB
The access processing thread means that it has been accepted normally.

Thereafter, in step ST8, a DB access process is executed. That is, connect to the database,
Executes SQL which is a database access language. Then, in step ST9, with the end of the DB access processing, the number of connections is counted down.
At 10, the DB access queue is deleted. And
According to the contents of the DB access processing thread, for example, if the data is a data reference, the result is transferred to the DB access processing thread. Is transferred.

[0018]

According to the present invention, since the number of connections to the database is managed, there is an effect that the maximum number of connections can be controlled according to the driver for each DB-dedicated driver.

Further, the present invention can be used without any problem even if the DB-dedicated driver is not multi-thread compatible but single-thread compatible.

Further, according to the present invention, since the access to the database is queue-managed, it is possible to efficiently control the access and to improve the overall performance.

[Brief description of the drawings]

FIG. 1 is a diagram for illustrating a database access configuration of the present invention.

FIG. 2 is a flowchart showing a detailed operation of the database access management illustrated in FIG. 1;

FIG. 3 is a diagram showing database access according to the prior art.

[Explanation of symbols]

 10 Database 12 Database dedicated driver 14 Database driver manager 15 Database access management 16 Database API 18 Database access processing

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 5B075 KK02 KK42 5B085 AC03 BG06

Claims (2)

[Claims] 1. A database, a database driver for controlling access to the database, a database driver manager for managing the database driver and connecting to the database, a database access process, and the database driver manager A database access control system comprising: a database application programming interface that is a connection interface with the database driver; a means for setting a maximum number of connections determined by specifications of the database driver or the entire system; and database access from each thread of the database access processing. Centrally manages and controls the number of concurrently required database access processing threads to be less than the set maximum number of connections Database access control system characterized by the database access management means for managing, with the. 2. A database, a database driver for controlling access to the database, a database driver manager for managing the database driver and connecting to the database, a database access process, and the database driver manager A database application programming interface which is a connection interface with the database access control method for controlling access to a database, comprising: setting a maximum number of connections determined by specifications of the database driver or the entire system; Centrally manages and controls database access from each thread, and reduces the number of simultaneously required database access processing threads Manage below the maximum number of connections constant been, database access control method characterized by.