JPH08292956A - Device and method for data base management - Google Patents

Abstract

PURPOSE: To provide a multithread type data base managing device and its method which enable a preferential execution to a specific thread by performing a priority level control. CONSTITUTION: When there is a thread which is newly generated by a priority level control means 4, a dispatch means 1 sets a priority level for this thread. A thread having high priority is selected out of all executable threads according to the priority and the thread is executed. Thus, the dispatch means 1 assigns a CPU time according to the priority, so a data base system is provided which can effectively execute the work.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to management of a database that processes access requests to a database from a plurality of clients while dividing the request into a plurality of threads. In particular, the present invention relates to multi-thread type database management in which control is transferred to each thread based on priority control.

[0002]

2. Description of the Related Art A so-called multi-thread server type database management in which access requests from a plurality of clients are divided into processing units (threads) and scheduled by one server process by one process The method is widely used. FIG. 7 shows an explanatory diagram of a multi-thread type database management method described in, for example, "Nikkei Data Pro Open Series Open System 1, 1994, 9, OS3-2020". As shown in FIG.
The dispatch means 1 uses threads (5
It has a function to transfer the control of processing to 9). The sequence means 2 monitors the progress of the processing of the threads (5 to 9) to which the control of the processing has been transferred, and instructs the processing to be performed next. Further, the database access means 3 accesses the database based on the instruction of the sequence means 2. The thread (5
9 to 9) are generated by the clients 10 and 11.

In the conventional multi-threaded database management system as shown in FIG. 7, when a client 10 or 11 requests a database processing, the thread (5 to 9) as the processing unit is processed. Is generated. The dispatch means 1 appropriately selects a processable thread and transfers the control of the process to this selected thread. The sequence means 2 monitors the progress of the processing of the selected thread, and instructs the database access means 3 to perform the next database processing.

[0004]

As described above, the conventional multi-thread type database management system does not control the threads (5 to 9) by priority. That is, the dispatch means 1 has selected a thread that can be executed at present from the threads (5 to 9), and has not selected the thread to which the control is transferred by controlling the priority. Therefore, even if there is a thread that wants to execute processing preferentially, that thread cannot be processed preferentially.

As a result, there has been a problem that, for example, the privileged handling of preferentially processing the database processing involved in a specific work cannot be performed.

The present invention has been made to solve the above problems, and its purpose is to provide a priority to each thread in the management of a multi-thread type database and to control a specific thread by so-called priority control. It is possible to execute it preferentially.

[0007]

In order to solve the above-mentioned problems, the first invention is a dispatch means for transferring control of processing to a thread generated by a client access request to a database, and said dispatch means. Sequence means for outputting a predetermined instruction based on a processing sequence of a thread whose control of processing has been reserved by; and a data base access means for accessing a data base based on the predetermined instruction of the sequence means, In the multi-thread type database management device having the above-mentioned, the dispatch means gives a priority order to the generated threads at the time of thread generation, allocates CPU time to the generated threads in accordance with this priority order, and thereafter generates the generated threads. Priority to transfer control of processing to the created thread Position control means, a database management system which comprises a.

A second aspect of the present invention, in order to solve the above-mentioned problems, in the database management device of the first aspect of the present invention, the dispatch means further comprises: when the dispatch means gives priority to the threads, Privilege priority is given to a specific thread, and control of thread processing is transferred preferentially to a thread having this privilege priority, and until the thread having the privilege priority explicitly finishes processing, privilege The database management apparatus is characterized by including second priority control means for transferring control of processing only to threads having priorities.

A third aspect of the present invention, in order to solve the above-mentioned problems, in the database management apparatus of the second aspect of the present invention, the dispatch means further comprises: when the dispatch means gives priority to the threads, When a plurality of threads to which the privilege priority has been given already exist, third priority control means for preferentially transferring processing to a thread having a higher priority priority is included. A characteristic database management device.

In order to solve the above-mentioned problems, a fourth aspect of the present invention is directed to the database management device of the first aspect of the present invention, wherein the dispatching means further sets a priority order for the threads to generate threads. When giving a priority to a thread, if there is a thread having a privilege priority, the thread processing control is preferentially transferred to the thread having a privilege priority,
Until the thread having the privilege priority explicitly finishes the processing, the processing control is transferred only to the thread having the privilege priority, and after the processing of the thread having the privilege priority is completed, another thread is executed in accordance with the priority. And a fourth priority control means for shifting the processing to.

A fifth aspect of the present invention, in order to solve the above-mentioned problems, in the database management device of the first aspect of the present invention, the dispatching means further sets a priority order for the threads to generate threads. In the database management apparatus, a fifth priority control means is provided for giving priority to a thread based on the processing content of the thread when performing the operation, and transferring control of the processing to the thread according to this priority. is there.

In order to solve the above problems, a sixth aspect of the present invention is the database management device according to the first aspect of the present invention, wherein the dispatching means further sets a priority order for the threads and creates a thread. The database management apparatus is characterized by including a sixth priority control means for giving a priority to each thread for each user when performing, and transferring control of processing to the thread according to this priority.

In order to solve the above problems, a seventh aspect of the present invention is the database management device according to the first aspect of the present invention, wherein the dispatching means further sets a priority order for the threads to generate threads. When you do, give the thread a priority for each terminal,
The database management apparatus is characterized by including seventh priority control means for transferring processing control to the thread in accordance with this priority.

In order to solve the above-mentioned problems, an eighth aspect of the present invention is the database management apparatus according to any one of the first to seventh aspects of the present invention, wherein the dispatch means further changes the priority order given to the threads. The database management apparatus is characterized by including priority order changing means for changing the priority.

In order to solve the above problems, the ninth aspect of the present invention reserves control of processing by a dispatch step in which control of processing is transferred to a thread generated by a request from a client to access a database. Based on the sequence of processing of the thread
In a multithreaded database management method comprising a sequence step of outputting a predetermined instruction and a data base access step of accessing a data base based on the predetermined instruction of the sequence step, the dispatch step includes A first priority control step of giving a priority to the generated threads when the threads are generated, allocating CPU time to the generated threads according to this priority, and then transferring control of processing to the generated threads, It is a database management method characterized by including.

A tenth aspect of the present invention, in order to solve the above-mentioned problems, is the database management method according to the ninth aspect of the present invention, wherein the dispatch step further specifies when the dispatch step gives priority to the thread. Priority priority is given to the thread of the priority level, the control of the thread processing is preferentially transferred to the thread having this privilege priority, and the priority priority is given until the thread having the privilege priority explicitly finishes the processing. A database management method comprising a second priority control step of transferring control of processing only to threads having priorities.

An eleventh aspect of the present invention is, in order to solve the above-mentioned problems, in the database management method according to the tenth aspect of the present invention, the dispatch step further comprises: when the dispatch step gives priority to the thread, When a plurality of threads to which the privilege priority has been given already exist, a third priority control step of preferentially transferring processing to a thread having a higher priority priority is included. It is a characteristic database management method.

A twelfth aspect of the present invention, in order to solve the above-mentioned problems, in the database management method according to the ninth aspect of the present invention, in the dispatch step, the dispatch step further sets a priority for the thread. When a thread is created, a priority is given to the thread, and if a thread having a privilege priority exists, the thread processing control is preferentially transferred to the thread having the privilege priority, and the thread having the privilege priority is given. Until the processing explicitly ends the processing, the processing control is transferred only to the thread having the privilege priority, and after the processing of the thread having the privilege priority is completed, the processing is transferred to another thread according to the priority. A database management method including a priority control step.

A thirteenth aspect of the present invention is, in order to solve the above-mentioned problems, in the database management method according to the ninth aspect of the present invention, the dispatch step further comprises the step of prioritizing the threads by the thread. A fifth priority order control step of giving a priority to a thread based on the processing content of the thread at the time of generation, and transferring the control of the processing to the thread in accordance with the priority order. Is.

A fourteenth aspect of the present invention, in order to solve the above-mentioned problems, in the database management method according to the ninth aspect of the present invention, in the dispatch step, the dispatch step further sets a priority to the thread. The database management method is characterized by including a sixth priority order control step of giving priority to a thread for each user at the time of generation and transferring control of processing to the thread according to this priority order.

A fifteenth aspect of the present invention, in order to solve the above-mentioned problems, in the database management method according to the ninth aspect of the present invention, in the dispatch step, the dispatch step further sets a priority to the thread. A database management method characterized by including a seventh priority order control step of giving a priority to a thread for each terminal method at the time of generation and transferring control of processing to the thread according to this priority order.

In order to solve the above problems, the 16th aspect of the present invention is the database management method according to the ninth to fifteenth aspects of the present invention, wherein the dispatching step further assigns the priority order given to the threads. It is a database management method characterized by including a priority changing step of changing dynamically.

[0023]

The first priority control means in the first aspect of the present invention gives priority to the generated threads, and the processing control is transferred to the threads based on this priority. Therefore, the priority of processing can be set among the threads, and efficient work can be performed.

The second priority control means in the second aspect of the present invention transfers control of processing only to the thread having the privilege priority until the thread having the privilege priority explicitly finishes the processing. Therefore, even when it is desired to execute only the thread while eliminating the others, it is possible to efficiently perform the work.

In the third priority control means in the third aspect of the present invention, when there are a plurality of threads to which the privilege priority is given, the processing is preferentially moved from the thread having the higher priority. Therefore, even when there are a plurality of privileged priorities, efficient work can be performed.

In the fourth priority control means in the fourth aspect of the present invention, after the processing of the thread having the privilege priority is completed, the processing is transferred to another thread according to the normal priority. Therefore, it is possible to efficiently process a thread having a privilege priority and a thread having only a normal priority.

The fifth priority control means in the fifth aspect of the present invention gives the priority based on the processing contents of each thread. Therefore, it is possible to efficiently carry out the work.

The sixth priority control means in the sixth aspect of the present invention gives each thread a priority for each user. Therefore, it is possible to efficiently carry out the work for each user.

The seventh priority control means in the seventh aspect of the present invention gives priority to each thread for each terminal device. Therefore, it is possible to efficiently perform the work for each terminal device.

The eighth priority changing means according to the eighth aspect of the present invention dynamically changes the priority of a thread to which a priority is once assigned. Therefore, when it is desired to change the processing priority of each thread during the execution of the work, it is possible to flexibly deal with it.

The ninth to sixteenth inventions are database management methods realized by the database management apparatus of the first to eighth inventions. Therefore, the ninth to 16th aspects of the present invention have the same operation as the first to eighth aspects of the invention.

[0032]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT A preferred embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 is an explanatory view for explaining a database management apparatus and a database management method which are preferred embodiments of the present invention. As will be understood by comparing the explanatory view shown in FIG. 1 with FIG. 7 for explaining the conventional database management apparatus, the priority control means 4 is a characteristic configuration in this embodiment. In addition, in FIG.
The operation of the dispatch means 1 for selecting a thread based on priority and executing this thread is shown.

First, when the client 10 or 11 requests a processing regarding a database, threads (5 to 9) for performing the processing are generated. Then, the dispatch means 1 checks in step 21 whether there is a thread newly created by the priority control means 4.

As a result of the check, if it is determined that there is a newly created thread, the priority control means 4 sets the priority to the newly created thread in step 2
Set in 2.

When the priority order is set in step 22, the priority order control means 4 sets the thread (5
9-9), the table storing the thread ID, the priority, and the thread state information is updated. That is, in step 23, to the thread ID and priority correspondence table,
The ID of the created thread, the given priority of the thread, and the information indicating the status information of the thread are registered.

The thread status information here is, for example, "executable" or "input / output wait". After the registration is performed, the priority control means 4 determines, based on the status information registered in the table as shown in FIG.
It is checked whether all the registered threads can be executed (step 24).

If it is determined in step 24 that there is an executable thread, the priority control means 4
Refers to the priority information registered in the table shown in FIG. 3 and checks whether or not the privilege priority is given to all the executable threads (step 25).

When it is determined in step 25 that the privilege priority is given to the predetermined thread, the priority control means 4 further selects from the executable threads having the privilege priority. A thread to be executed is selected based on the priority (step 26).

Then, the dispatch means 1 uses the CPU so that the thread having the privilege priority will occupy the CPU time unless the thread explicitly finishes the processing.
Allocate time to execute the selected thread (with privilege priority) (step 27).

On the other hand, when it is judged in step 25 that there is no thread to which the privilege priority is given, the priority control means 4 in the dispatch means 1
Refers to the priority order information registered in the table as shown in FIG. 3 and selects a thread to be executed next based on the priority order from the executable threads (step 28).

Then, the dispatch means 1 allocates the CPU time based on the priority and executes the selected thread (step 29).

After the threads are executed in steps 27 and 29 in this manner, the dispatch means 1 checks by the priority control means 4 whether or not the processing end is indicated as a processing request from the client. (Step 30). When it is determined that the executed thread is indicated as the processing end by the processing request, the dispatch means 1 uses the priority ID control means 4 from the thread ID and the priority correspondence table as shown in FIG. The entry related to the thread is deleted (step 31).

When it is judged that the executed thread does not indicate the end of processing as the processing request, the dispatch means 1 causes the priority control means 4 to display the thread ID and the priority correspondence table in the thread ID shown in FIG. Registers the thread state information regarding (step 32).

The fact that the processing end is indicated as the processing request means that the end processing is requested as a request from the thread to the dispatch means 1.

As the setting of the priority as the thread selection criterion, it is possible to set it for each processing content of the thread such as reference and update to the database. Further, it is preferable that the priority order is set for each user and each terminal.

When the priority order is set according to the processing contents of the thread such as reference and update to the database, the priority order controlling means 4 refers to, for example, a previously created correspondence table of the processing contents and the priority order, and The priority order is set based on the processing content. The correspondence table of the processing contents and the priority order is a table as shown in FIG. 4, for example. As shown in FIG. 4, when the processing content is “select”, the priority is 20, and the processing content is “dele”.
"te" is set as the priority order 60. In this way, based on the processing content of the thread, the thread ID and the priority order correspondence table as shown in FIG. 3 are registered.

Further, when the priority order is set for each user, it is preferable that the priority order is set by referring to the correspondence table of the user and the priority order created in advance in the priority order control means 4, for example. Is. Such a correspondence table of users and priorities is, for example, a table as shown in FIG. As shown in FIG. 5, for example, when the user is “John”, the priority is set to 60, and when the user is “Eric”, the priority is set to 40.

Further, when the priority order is set for each terminal, the priority order control means 4 refers to, for example, a correspondence table between the terminals and the priority order created in advance, and sets the priority order for each thread. Is desirable. For example, an example of a correspondence table of such terminals and priorities is shown in FIG. As shown in FIG. 6, for example, the terminal
If it is “001”, the priority is 30, and the terminal is “T00.
When it is "6", the priority order 20 is set. Based on such a correspondence table, based on the terminal associated with the thread, registration is performed in the correspondence table of the thread ID and priority shown in FIG. 3 based on the thread terminal shown in FIG.

In the present embodiment, the thread priority is set with reference to a correspondence table of thread processing and priority created in advance as shown in FIG. 5, for example. It is also preferable to dynamically change the priority of the thread later. As described above, by dynamically changing the priority order, the database management apparatus and the database management method can flexibly cope with the case where the priority order of each terminal or processing is changed during the processing of the database. Is obtained.

[0051]

As described above, according to the present invention, by executing a thread based on priority control, it is possible to perform processing such as preferentially processing a database processing involved in a specific job. It is possible to build a flexible database system.

Specifically, according to the first aspect of the present invention, by performing so-called priority control, it is possible to construct a database system capable of efficiently performing work.

According to the second aspect of the present invention, it is possible to obtain a database system in which execution of other threads can be eliminated and only predetermined threads can be executed. Therefore, it is possible to provide a flexible database system that can handle extremely urgent processing.

According to the third aspect of the present invention, a database system capable of efficient operation can be realized even when there are a plurality of threads to which privileged priorities are given.

According to the fourth aspect of the present invention, after the processing of the thread having the privilege priority is completed, the processing of the other threads is performed in accordance with the priority, so that the thread having the privilege priority and the normal thread are processed. A database system that can be efficiently executed can be realized.

According to the fifth aspect of the present invention, since the priorities are given based on the processing contents of the threads, it is possible to provide a database system capable of more efficient processing.

According to the sixth aspect of the present invention, it is possible to obtain a database system capable of efficient work in which priority is given to each user.

According to the seventh aspect of the present invention, since a priority is given to each terminal device, a database system capable of efficient operation for each terminal device can be obtained.

According to the eighth aspect of the present invention, since the priorities given to the threads can be dynamically changed, it is possible to obtain a flexible database system capable of promptly responding to changes in the priorities.

According to the ninth to sixteenth inventions, the database management method executed by the first to eighth database management devices can be realized, and the first to eighth inventions can be realized.
The same effects as those of the present invention of the first through eighth aspects are obtained.

[Brief description of drawings]

FIG. 1 is an explanatory diagram illustrating a database management apparatus and a database management method according to a preferred embodiment of the present invention.

FIG. 2 is a flow chart for explaining the operation of the dispatch means 1 of this embodiment.

FIG. 3 is an explanatory diagram showing a table referred to by a priority control unit of this embodiment.

FIG. 4 is an explanatory diagram showing a table referred to by a priority control unit of this embodiment.

FIG. 5 is an explanatory diagram showing a table referred to by a priority control unit of this embodiment.

FIG. 6 is an explanatory diagram showing a table referred to by a priority control unit of this embodiment.

FIG. 7 is an explanatory diagram showing a conventional database management method.

[Explanation of symbols]

1 dispatch means, 2 sequence means, 3 database access means, 4 priority control means, 5,
6,7,8,9 threads, 10,11 clients.

Claims (16)

[Claims] 1. A dispatch means for transferring control of processing to a thread generated by a client access request to a database, and a predetermined instruction based on a processing sequence of a thread whose processing control is reserved by the dispatch means. In a multi-threaded database management device comprising: a sequence means for outputting a data base; and a data base access means for accessing a data base based on the predetermined instruction of the sequence means. A first priority control means for giving a priority order to the generated threads, allocating CPU time to the generated threads according to the priority, and then transferring control of processing to the generated threads. Database management system characterized by . 2. The database management device according to claim 1, wherein the dispatch means further gives a privilege priority to a specific thread when the dispatch means gives the thread priority. Second, control of thread processing is preferentially transferred to a thread having privilege priority, and control is transferred only to thread having privilege priority until the thread having privilege priority explicitly finishes processing. A database management device comprising: priority control means. 3. The database management device according to claim 2, wherein the dispatch means further includes a plurality of threads to which the privilege priority has been given when the dispatch means gives priority to the threads. And a third priority control means for preferentially transferring processing to a thread having a high priority privilege. 4. The database management device according to claim 1, wherein the dispatch unit further assigns a priority to the thread when the dispatch unit sets the priority of the thread and creates a thread, If there is a thread with priority, the thread's processing control is preferentially transferred to the thread with privilege priority, and the privilege priority is changed until the thread with privilege priority explicitly finishes processing. A database management device, comprising: fourth priority control means for transferring processing control only to the owning thread, and after processing of the thread having the privilege priority is completed, transferring the processing to another thread according to the priority. . 5. The database management device according to claim 1, wherein the dispatching unit is further configured for the thread based on the processing content of the thread when the dispatching unit sets the priority of the thread and creates the thread. A priority control means for giving priority to the thread and transferring control of processing to the thread according to the priority. 6. The database management device according to claim 1, wherein the dispatching unit further sets a priority for the thread when the dispatching unit sets a priority for the thread, and prioritizes the thread for each user. And a sixth priority control means for transferring processing control to the thread according to this priority. 7. The database management device according to claim 1, wherein the dispatching unit further sets a priority for the thread for each terminal when the dispatching unit sets a priority for the thread and creates a thread. And a seventh priority control means for transferring processing control to the thread according to this priority. 8. The database management device according to claim 1, wherein the dispatch unit further includes a priority order changing unit that dynamically changes the priority order given to the thread. A database management device characterized by. 9. A predetermined instruction based on a dispatch step of transferring control of processing to a thread generated in response to a database access request from a client, and a processing sequence of a thread whose control of processing is reserved by the dispatch step. In a multi-threaded database management method, the sequence step of outputting a data base, and a data base access step of accessing a data base based on the predetermined instruction of the sequence step. A first priority control step of giving a priority to the created threads at times, allocating CPU time to the created threads according to this priority, and then transferring control of processing to the created threads. Database management method characterized by . 10. The database management method according to claim 9, wherein the dispatch step further gives a privilege priority to a specific thread when the dispatch step gives the thread priority. Second, control of thread processing is preferentially transferred to a thread having privilege priority, and control is transferred only to thread having privilege priority until the thread having privilege priority explicitly finishes processing. A database management method comprising: a priority control step. 11. The database management method according to claim 10, wherein in the dispatch step, when the dispatch step gives priority to the threads, a plurality of threads to which the privilege priority has been given already exist. And a third priority control step of preferentially transferring processing to a thread having a privilege priority of a high priority, the database management method. 12. The database management method according to claim 9, wherein the dispatch step further assigns a priority to the thread when the dispatch step sets a priority for the thread and creates a thread, If there is a thread with priority, the thread's processing control is preferentially transferred to the thread with privilege priority, and the privilege priority is changed until the thread with privilege priority explicitly finishes processing. A fourth priority control step of transferring control of processing only to the owning thread, and after processing of the thread having the privilege priority is completed, transferring the processing to another thread according to the priority, . 13. The database management method according to claim 9, wherein the dispatching step is further based on a thread processing content for the thread when the dispatching step sets a priority for the thread and creates the thread. A fifth priority control step of giving priority to each thread and transferring control of processing to the thread according to the priority. 14. The database management method according to claim 9, wherein the dispatch step further sets a priority for the thread for each user when the dispatch step sets a priority for the thread and creates a thread. And a sixth priority control step of transferring control of processing to the thread according to this priority order, and a database management method. 15. The database management method according to claim 9, wherein in the dispatch step, when the dispatch step sets a priority for the thread and creates a thread, the thread is prioritized for each terminal method. And a seventh priority control step of transferring control of processing to the thread according to this priority, and the database management method. 16. The database management method according to claim 9, wherein the dispatch step further includes a priority order changing step of dynamically changing the priority order given to the thread. Database management method characterized by.