JPH10320258A - File access device and machine-readable recording medium recorded with program - Google Patents

Abstract

PROBLEM TO BE SOLVED: To speed up retrieving processing by inhibiting an exclusive controller from executing exclusive control for a retrieval request (non-exclusive retrieval request) allowing the reading of data stored in each exclusive unit during the updating processing of the data by another user's program. SOLUTION: An access method determination means 104 judges whether a data access request from a user program 101 is an nonexclusive retrieval request or not. An exclusive control means 141 exclusively controls a data access request judged as a request other than a non-exclusive retrieval request by the means 104 and access means 110, 111 execute a data access request allowed to be executed by the means 114 and a data access request judged as a non-exclusive retrieval request by the means 104.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a technology for processing a data access request for a database file, and more particularly to a technology for processing a data access request so that a search process can be performed at high speed.

[0002]

2. Description of the Related Art Exclusive control of a data access request to a database file has been conventionally performed in order to prevent inconsistency in the database file. In general exclusive control, exclusion is performed using pages, blocks, and the like as target units (exclusive units) of exclusive control. When a certain exclusive unit is updated and exclusive, the exclusive unit is released until the exclusive unit is released. Subsequent data access requests are made to wait regardless of the request type.

[0003] This is because even if the subsequent data access request is a search request, if the request is for an exclusive unit that has been updated and exclusive, the inconsistency caused by referring to the data that is being updated will be avoided. The idea of completely eliminating it was common. But then,
System throughput will inevitably decrease.

Therefore, in order to solve such a problem, even if a certain exclusive unit is updated and exclusive, if the update processing is not actually performed on the exclusive unit, a search is performed. A technique for permitting processing has been proposed (for example, Japanese Patent Laid-Open No. 2-224152). That is, in the above-described conventional technology, the second exclusive identification information is used separately from the normal exclusive identification information, and the update processing is performed when the second exclusive identification information is already updated exclusively or search exclusive. Wait until it is released, if it is not exclusive, make it exclusive until the end of the update process. If the second exclusion identification information is not already update exclusive, do the search exclusive until the end of the search process. I have to.

[0005]

The use of the database system requires high-speed processing as in the case of obtaining an approximate number of data that meets a certain condition, but does not require much accuracy. There are usage forms. In such a usage form, the data stored in the exclusive unit being updated by another user program may be read, that is, either the content before the update or the content after the update is read. Even if it is uncertain whether to read, it is only necessary to know the rough estimate, so that the purpose can be achieved.

However, according to the conventional technique described in Japanese Patent Application Laid-Open No. 2-224152, an exclusive unit for which an update process is being performed is subject to exclusive control even with a search request as described above. Since the search process is kept waiting until the update process is completed, there is a problem that a sufficient processing speed cannot be obtained.

Further, some conventional file access devices include a plurality of pages (for example, one track, one cylinder, etc.) stored in a database file in order to reduce the processing time involved in data input / output. There is a device that supports a data access request that can collectively access the data of (Page No.). In such an apparatus, since the number of exclusive units to be excluded by one data access request is large, the number of requests competing for exclusive control increases, and the probability of waiting for each data access request is higher than that of the above-described prior art. And the above problem becomes more pronounced.

Therefore, an object of the present invention is to define a search request that can read data stored in an exclusive unit being updated by another user program as a non-exclusive search request,
An object of the present invention is to eliminate a non-exclusive search request from a target of exclusive control so that a search process can be sped up.

[0009]

In order to achieve the above object, a file access device for processing a data access request for a database file according to the present invention comprises a user program (101 in FIG. 1).
Access method determining means (104 in FIG. 1) for determining whether or not the data access request is a non-exclusive search request
And an exclusive control unit (11 in FIG. 1) that performs exclusive control on the data access request determined by the access method determination unit (104 in FIG. 1) to be a request other than a non-exclusive search request.
4) and the data access request permitted to be executed by the exclusive control means (114 in FIG. 1) and the data access request determined to be a non-exclusive search request by the access method determination means (104 in FIG. 1). Access means (11 in FIG. 1)
0,111).

In this configuration, when a data access request is issued from the user program (101 in FIG. 1), the data access request is a non-exclusive search request by the access mode determining means (104 in FIG. 1). It is determined whether there is. The exclusive control means (114 in FIG. 1) performs exclusive control on the data access request determined by the access mode determination means (104 in FIG. 1) to be a request other than the non-exclusive search request, and the access means (110 in FIG. 1). , 111)
Then, the data access request permitted to be executed by the exclusive control means (114 in FIG. 1) and the data access request determined as the non-exclusive search request by the access mode determination means (104 in FIG. 1) are executed.

In addition, the present invention supports a data access request that can collectively access a plurality of pages of data stored in a database file in order to reduce the processing time involved in data input / output. In order to achieve the above object, even in the file access device which performs the above, there is no data access request from the user program (101 in FIG. 1) for requesting the collective access to the data of a plurality of pages. Access method determining means (104 in FIG. 1) for determining whether or not the request is an exclusive search request;
Exclusive control means (114 in FIG. 1) for exclusively controlling the data access request determined by the access method determining means (104 in FIG. 1) to be a request other than a non-exclusive search request.
An access means for executing a data access request permitted to be executed by the exclusive control means (114 in FIG. 1) and a data access request determined to be a non-exclusive search request by the access method determination means (104 in FIG. 1). (110 in FIG. 1)
And

In this configuration, when a user program (101 in FIG. 1) issues a data access request for requesting simultaneous access to a plurality of pages of data, the access method determining means (101). It is determined whether or not the data access request is a non-exclusive search request according to 104) in FIG. The exclusive control means (114 in FIG. 1) performs exclusive control on the data access request determined by the access mode determination means (104 in FIG. 1) to be a request other than the non-exclusive search request, and the access means (110 in FIG. 1). ,
At 111), the data access request permitted to be executed by the exclusive control means (114 in FIG. 1) and the data access request determined as the non-exclusive search request by the access mode determination means (104 in FIG. 1) are executed.

Further, in the file access apparatus of the present invention, a large amount of system memory is used by a specific user program for performing batch access, and another user program terminates abnormally due to lack of memory. In order to prevent such a situation, a file access device that processes a data access request for requesting a batch access to data of a plurality of pages to a database file storing a plurality of tables composed of a plurality of pages is provided. A concurrent execution number setting means (FIG. 1) for setting a batch accessible upper limit number indicating the upper limit of the number of batch accessible tables requested by the batch access setting request from the user program (101 in FIG. 1). 103) and data of a plurality of pages from the user program (101 in FIG. 1). If the data access request for access to a certain table is for a certain table, and the batch access of the data access request is permitted, the user program (101 in FIG. 1) is set as a target of the batch access. It is determined whether or not the number of tables to be executed exceeds the batch accessable upper limit set by the concurrent execution number setting means (103 in FIG. 1), and the data access request is a non-exclusive search request. Access method determining means (104 in FIG. 1) for determining whether or not the data access request is a request other than a non-exclusive search request by the access method determining means (104 in FIG. 1). Exclusive control means (114 in FIG. 1) and the access method determining means (104 in FIG. 1) permitted to be executed by the exclusive control means (114 in FIG. 1). A data access request determined not to exceed the batch accessable upper limit number and a data access request determined by the access method determining means (104 in FIG. 1) to be a batch access accessible upper limit number and determined to be a non-exclusive search request. Request and a collective access unit (110 in FIG. 1) and the exclusive control unit (FIG. 1).
The data access request which is permitted to be executed at 114) and is judged to exceed the batch accessable upper limit number by the access method determining means (104 of FIG. 1), and the data access request by the access method determining means (104 of FIG. 1). A page access means for executing a data access request exceeding the accessible maximum number and determined to be a non-exclusive search request (FIG. 1)
111).

In this configuration, when a batch access setting request is issued from the user program (101 in FIG. 1), the concurrent execution number setting means (103 in FIG. 1) sets the batch request in response to the batch access setting request. Set the maximum number of accessible batches.

Thereafter, the user program (1 in FIG. 1)
01), when a data access request for a certain table is issued, which requests to collectively access data of a plurality of pages, the access method determining means (10 in FIG. 1)
4), when the batch access of the data access request is permitted, the number of tables to be collectively accessed by the user program (101 in FIG. 1) is set by the concurrent execution number setting means (103 in FIG. 1). It is determined whether or not the total number of accessible batches exceeds the upper limit, and whether or not the data access request is a non-exclusive search request.

The exclusive control means (114 in FIG. 1) performs exclusive control on the data access request determined by the access method determining means (104 in FIG. 1) to be a request other than the non-exclusive search request.

Also, batch access means (110 in FIG. 1)
Then, the data access request permitted to be executed by the exclusive control means (114 in FIG. 1) and determined by the access method determination means (104 in FIG. 1) not to exceed the collectively accessible maximum number, and the access method determination means (104). A data access request that does not exceed the batch accessible maximum number and is determined to be a non-exclusive search request in 104) in FIG. 1 is executed. on the other hand,
In the page unit access means (111 in FIG. 1), the data which is permitted to be executed by the exclusive control means (114 in FIG. 1) and which is judged by the access method determination means (104 in FIG. 1) to exceed the collectively accessible upper limit number. An access request and a data access request that exceeds the batch accessable upper limit number and is determined to be a non-exclusive search request by the access method determination unit (104 in FIG. 1) are executed.

[0018]

Embodiments of the present invention will now be described in detail with reference to the drawings.

FIG. 1 is a block diagram showing an embodiment of the present invention. A user program 101, processing request control means 102, concurrent execution number setting means 103, access method determination means 104, and processing execution It comprises a control means 105, an access information storage area 106, a database file access means 109, and a plurality of database files 112-1 to 112-n storing a plurality of tables.

The user program 101 has a function of outputting a batch access setting request, a data access request, and a batch access stop request.

The batch access setting request output by the user program 101 includes a processing target ID (table table ID and file ID of a database file including the table) for specifying a table for which batch access is desired. ), And the upper limit of the number of tables that can be accessed at the same time (batch accessible maximum number).

The data access request includes a processing target ID for specifying a table to be accessed (consisting of a table ID of a table and a file ID of a database file including the table), a database operation instruction, Search mode information (information indicating whether the request is a non-exclusive search request that allows reading of data stored in an exclusive unit that has not yet reached the commit point and has been updated by another user program) ).

The batch access stop request includes a processing target ID (table ID of the table) for specifying the table for which batch access is to be stopped.
And a file ID of a database file including the table).

When a batch access setting request or a batch access stop request is output from the user program 101, the processing request control means 102 sets the simultaneous execution number setting means 103.
To the batch access setting request and the batch access stop request. When a data access request is output from the user program 101, the access method determining unit 10
4 is passed the data access request.

The access information storage area 106 is secured in a memory area unique to the user program 101, and stores table control information 107 and collective access determination information 108.

The table control information 107 contains the user program 1
01 includes a table ID of a table for which batch access is desired and a file ID of a database file including the table. Also,
The collective access determination information 108 includes a collective access upper limit number, a collective access number indicating the number of tables to be collectively accessed, and a collective access processing target ID indicating a processing target to be collectively accessed.

FIG. 2 is a diagram showing an example of the contents of the access information recording area 106. In this example, three pieces of table control information 1
07-a to 107-c and collective access determination information 108
And are stored. Table control information 107-a to 107-
c includes table IDs “H1 to H3” of Tables A to C, respectively.
A file ID “F1” of a database file (referred to as a database file 112-1) including tables A to C is set. In the collective access determination information 108, “2” is set as the collective access upper limit number 108-1, “0” is set as the collective access number 108-2, and what is the collective access processing target ID 108-3. Is also not set.

According to the batch access setting request issued from the user program 101, the concurrent execution number setting means 103 stores the table control information 107 and the batch access judgment in the access information storage area 106 which is a memory area unique to the user program 101. Information 108 is stored. Further, according to the batch access stop request issued from the user program 101, the batch access number 108-2 in the batch access determination information 108 is decremented by one, and the batch access processing target ID 108
The processing target ID requested to be canceled is deleted from the processing target IDs set to -3. When a collective access setting request and a collective access stop request are issued from another user program (not shown), the same processing as described above is performed on the access information storage area unique to the user program. .

When a data access request is issued from the user program 101 or another user program (not shown), the access method determining means 104 determines the access method of the data access request as a batch access (a plurality of continuous pages). Or batch access) or a page-level access,
It has a function of determining whether or not the data access request is subject to exclusive control.

The processing execution control means 105 has a function of causing the database file access means 109 to perform access processing according to the contents determined by the access method determining means 104,
It has a function of returning the processing result of the database file access means 109 to the processing request control means 102, and the like.

The database file 112-1 stores a plurality of tables composed of a plurality of pages. Similarly, the other database files also store a plurality of tables each including a plurality of pages.

FIG. 3 shows the database files 112-1 to 112-1.
FIG. 3 is a diagram showing a relationship among a cylinder 201, a track 202, and a page 203 when 112-n is stored in a disk device. In this example, one cylinder is 6
Each track is divided into six pages. FIG. 4 shows a page 301 and a table 30.
FIG. 3 is a diagram showing a relationship between the track No. 2, 303 and a track. In this example, the table 302 with the table name A is stored in pages 8 to 15 and the table 303 with the table name B is stored in pages 16 to
It is stored on page 30.

Database file access means 109
Includes a batch access unit 110, a page unit access unit 111, and an exclusive control unit 114.

The batch access means 110 is a database file 112-i storing a table to be accessed.
It has a function to perform batch access to (1 ≦ i ≦ n). Here, the unit of collective access can be an arbitrary unit such as a track unit.

The page unit access unit 111 stores the database file 11 in which the table to be accessed is stored.
It has a function of performing page unit access to 2-i (1 ≦ i ≦ n).

The exclusive control means 114 has a function of exclusively controlling the data access request passed from the processing execution control means 105.

FIG. 5 is a flow chart showing an example of processing when setting the number of concurrent executions setting means 103, and FIG.
14 is a flowchart showing an example of the process of FIG.

When the user program 101 starts processing,
Process target I for specifying the table for which you want to access all at once
D and a batch access setting request including the batch accessible maximum number.

Now, for example, the batch access setting request issued from the user program 101 includes “H1, F1”, “H2, F1”, “H3, F1” as processing target IDs, "2" is included. Here, F1 is the database file 11
2-1 is a file ID, and H1, H2, and H3 are table IDs of tables A, B, and C stored in the database file 112-1. That is, the processing target ID included in the batch access setting request specifies the tables A, B, and C stored in the database file 112-1.

When the above-mentioned batch access setting request is issued from the user program 101, the processing request control means 1
02 transfers it to the concurrent execution number setting means 103.

Thus, the concurrent execution number setting means 103
Performs the process of the flow chart shown in FIG. 5, and first sets “2” in the collective access determination information 108 of the access information storage area 106 as the collective accessible maximum number 108-1 as shown in FIG. "0" is set as the number of batch accesses 108-2 (S1).

Thereafter, as shown in FIG. 2, the simultaneous execution number setting means 103 sets the table control information 1 for tables A, B, and C.
07-a, 107-b, and 107-c (including the table ID and the file ID) are stored in the access information storage area 106 (S2).

After issuing the batch access setting request, the user program 101 issues a data access request including a processing target ID for specifying a table to be accessed, a database operation instruction, and search mode information.

When a data access request is issued from the user program 101, the processing request control means 102 passes it to the access method determination means 104.

Thus, the access method determining means 104
Performs the processing shown in the flowchart of FIG.

First, based on the database operation command in the data access request, the access method determining means 104 determines whether the request requires search-based processing or update-based processing. (S11).

If it is determined that the request is for an update-type process (S11: no), the data access request is passed to the process execution control means 105, and the access method is set to page unit access. The processing execution control unit 105 is notified that the data access request is to be subjected to exclusive control (S19).

If it is determined that the request is for a search-related process (Yes in S11), the access information storage area 106 stores the table of the table indicated by the processing target ID set in the data access request. It is determined whether the table control information is stored (S12). That is, it is determined whether or not the data access request is for a batch access.

If it is determined that batch access is not requested (S12: no), the process of S17 is performed. In S17, it is determined whether or not the access request is a non-exclusive search request. When it is determined that the request is not a non-exclusive search request, the process of S19 is performed, and when it is determined that the request is a non-exclusive search request, the process execution control unit 1 is executed.
05, and notifies that the access method is page-based access and is not subject to exclusive control (S18). On the other hand, when it is determined that the batch access is requested (yes in S12).
Is the same processing target ID as the processing target ID set in the data access request.
It is determined whether it is set to medium (S13).

If it is determined in S13 that the setting has not been made (the determination result is no), the table for which the collective access is requested by the data access request is collectively accessed. It is determined whether or not it exceeds (S14).

If it is determined that the number does not exceed the collective access upper limit number (S14: no), the collective access number 108-2 in the collective access determination information 108 is incremented by one, and the collective access processing target ID 108-3 is added. The processing target ID set in the data access request is set (S15).

Thereafter, the access method determining means 104
Based on the search mode information set in the data access request, it is possible to read data stored in an exclusive unit that has not yet reached the commit point and has been updated by another user program. Is determined (S1).
6). Note that, also when the determination result in S13 is yes, the access method determination unit 104 performs the processing in S16.

When it is determined in S16 that the request is a non-exclusive search request (Yes in S16), the data access request is passed to the processing execution control means 105, the access method is set to the batch access method, and the exclusive control is performed. Is not performed (S21). On the other hand, if it is determined that the request is not a non-exclusive search request (No in S16), the data access request is passed to the processing execution control means 105, and the access method is set to the collective access method and the exclusive control is notified. (S20).

If it is determined in S14 that the total access limit is exceeded, it is determined whether the data access request is a non-exclusive search request (S17).

If it is determined that the request is a non-exclusive search request (Yes in S17), the data access request is passed to the processing execution control means 105, the access method is set to page unit access, and is not subjected to exclusive control. Is notified (S18). On the other hand, if it is determined in S17 that the request is not a non-exclusive search request, the process of S19 is performed.

When the data access request is passed from the access method determination means 104 and the access method is notified that the access method is to be batch access and is not subject to exclusive control, the process execution control means 105 sends the data access request to the database. It is passed to the batch access means 110 in the file access means 109. Thereby, the batch access means 1
A user program 101 executes a data access request and stores the read data for a plurality of continuous pages in a user program 101.
Is stored in a collective access input / output buffer (not shown) provided in a unique area of. This batch access input / output buffer is proportional to the batch accessible maximum number. The batch access unit 110 has a configuration capable of executing a plurality of data access requests in parallel.

When the data access request is passed from the access mode determining means 104 and the process execution control unit 105 is notified that the access mode is page unit access and is not subject to exclusive control, the data access control unit 105 executes the data access request. The request is passed to the page unit access unit 111 in the database file access unit 109. This allows
The page unit access unit 111 executes a data access request, and stores the read one page of data in a page unit access input / output buffer (not shown) provided in a unique area of the user program 101. The page unit access unit 111 has a configuration capable of executing a plurality of data access requests in parallel.

The processing execution control means 105 receives the data access request from the access method determination means 104 and, when notified that the access method is to be collectively accessed and subject to exclusive control, receives the data access request. To the exclusive control unit 114 in the database file access unit 109, and also notifies that the access method is batch access. The exclusive control unit 114 performs exclusive control of a data access request from the user program 101 and a data access request from another user program. If the data access request can be executed, the exclusive control unit 114 Hand over to 110. The collective access unit 110 executes a data access request, and stores the read data of a plurality of continuous pages in a collective access input / output buffer (not shown) provided in a shared area of the system.

When the data access request is passed from the access mode determining means 104 and the process execution control unit 105 is notified that the access mode is page unit access and exclusive control is to be performed, the process execution control unit 105 executes the data access request. The request is passed to the exclusive control means 114 in the database file access means 109, and the access method is notified that the access method is page unit access. Exclusive control means 1
14 performs exclusive control of a data access request from the user program 101 and a data access request from another user program, and if processing according to the data access request can be performed, It is passed to the page unit access means 111. Page unit access means 1
Reference numeral 11 executes a data access request and stores the read data for one page in a page-unit access input / output buffer (not shown) provided in the shared area of the system.

The processing execution control unit 105 reads data from the batch access input / output buffer and the page unit access input / output buffer unique to the user program 101, and transfers the read data to the user program 101 via the processing request control unit 102. Hand over to 101.

When a batch access stop request is issued from the user program 101, the concurrent execution number setting means 103 determines the number of batch accesses by the number of tables requested to stop batch access by the batch access stop request. The number of collective accesses 108-2 in the information 108 is decremented, and the processing target ID requested to be canceled is deleted from the processing target IDs set in the collective access target ID 108-3.

Next, the operation of the access mode determining means 104 will be described with a specific example of the contents of a data access request issued from the user program 101.

Now, for example, when the contents of the access information storage area 106 are as shown in FIG. 2, the user program 101 determines that the processing target ID is “H1” indicating Table A in the database file 112-1. , F1 ", a database access instruction is a" search instruction ", and a data access request with a search mode information of" no exclusive search request "is issued.

The processing request execution control means 102 passes the data access request to the access method determining means 104.

When the above-mentioned data access request is passed, the access method determining means 104 performs the processing shown in the flowchart of FIG.

In this example, since the database operation instruction is a “search instruction”, the result of the determination in S11 is “yes”.
Becomes Further, as shown in FIG. 2, since the table control information 107-a indicating the table A is stored in the access information storage area 106, the determination result in S12 is yes. Further, as shown in FIG.
Since no processing target ID is registered in
The judgment result of No. 3 is no. Further, as shown in FIG. 2, since the collective access upper limit number 108-1 is “2” and the current collective access number 108-2 is “0”, S1
The determination result of No. 4 is no.

As a result, the access method determining means 104
As shown in FIG. 7, the number of collective accesses 108-2 in the collective access determination information 108 is incremented by 1 and updated to "1", and the collective access processing target 108-3 is set in the data access request. Processing target ID “H1, F
"1" is set (S15).

Next, the access method determining means 104
Since the data access request allows reading of the page being updated (S16: yes), the process of S21 described above is performed.

Thereafter, from the user program 101, the processing target ID is stored in the table B in the database file 112-1.
Suppose that a data access request in which the database operation command is a "search command" and the search mode information is a "no exclusive search request" is issued.

Also in this case, S11, S12, S13, S
Since the result of the determination in step 14 is yes, yes, no, and no, the access method determining means 104 increments the number of collective accesses 108-2 in the collective access determination information 108 by 1 as shown in FIG. And adds the processing target ID “H2, F1” set in the data access request to the batch access processing target 108-3 (S1).
5).

Next, the access method determining means 104
Since the data access request allows reading of the page being updated (S16: yes), the process of S21 described above is performed.

Thereafter, from the user program 101, the processing target ID is stored in the table C in the database file 112-1.
Suppose that a data access request having a database operation command of "search command" and search mode information of "no exclusive search request" has been issued.

In this case, the determination results in S11, S12, and S13 are yes, yes, and no, as described above, but the number of batch accesses 108-2 is "2" as shown in FIG. Therefore, the determination result in S14 is yes. Therefore, in this case, the setting process (S15) for the collective access determination information is not performed. 9 in FIG. 9 indicates that the setting process (S15) is not performed.

If the determination in S14 is yes, the access method determining means 104 performs the processing in S17. In this case,
The data access request enables reading of a page being updated by another user program.
Is determined as yes, the access method determining unit 104 performs the processing of S18 described above.

Next, when the contents of the access information storage area 106 are as shown in FIG. 8, the user program 101 issues a batch request for stopping the batch access of the table B stored in the database file 112-1. The operation when the access stop request is output will be described. This batch access stop request includes the table ID “H2” of Table B and the file ID “F1” of the database file 112-1.

When the batch access stop request is issued from the user program 101, the processing request control means 10
2 passes it to the concurrent execution number setting means 103. As a result, the concurrent execution number setting means 103 decrements the number of collective accesses 108-2 in the collective access determination information 108 by 1 to “1”, and sets the processing ID “3” set in the collective access processing target ID 108-3. H2, F1 ". Thus, the state of the access information storage area 106 is as shown in FIG.

FIG. 10 is a block diagram showing an example of a hardware configuration of a file access device according to the present invention, which comprises a computer 1000 and a storage medium 1001 on which a file access program is recorded. The storage medium 1001 is a magnetic disk, a semiconductor memory, or another recording medium.

The file access program recorded on the recording medium 1001 is read by the computer 1000 constituting the file access device, and is read by the computer 10.
00, the processing request control means 102, concurrent execution number setting means 103, access method determination means 104, processing execution control means 105, and database file access means 109 shown in FIG. Realize.

[0079]

The first effect is that the search processing is speeded up for a search request (non-exclusive search request) which may read data stored in an exclusive unit being updated by another user program. The point is that you can do it.

The reason is that the non-exclusive search request is excluded from the subject of exclusive control.

A second effect is that a subsequent update request can be prevented from being waited for by a non-exclusive search request.

The reason is that the non-exclusive search request is excluded from the subject of exclusive control.

A third effect is to support a data access request that can collectively access a plurality of pages of data stored in a database file in order to reduce processing time involved in data input / output. Even in the file access device that performs this, the search processing for the non-exclusive search request can be speeded up.

The reason is that a non-exclusive search request for requesting simultaneous access to a plurality of pages has been excluded from the subject of exclusive control.

A fourth effect is that a large amount of memory of the system is used by a specific user program that performs batch access, and a situation in which another user program terminates abnormally due to insufficient memory can be prevented. It is.

The reason is that a user program is provided with a concurrent execution number setting means for setting the upper limit number of tables that can be accessed simultaneously (collectively accessible upper limit number).

[Brief description of the drawings]

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

FIG. 2 is a diagram showing an example of the contents of an access information storage area 106.

FIG. 3 is a diagram showing the relationship among cylinders, tracks, and pages.

FIG. 4 is a diagram showing a relationship between a table, a page, and a track.

FIG. 5 is a flowchart illustrating an example of a process performed by the simultaneous execution number setting unit 103 when setting;

FIG. 6 is a flowchart showing a processing example of an access method determining unit 104;

FIG. 7 is a diagram showing an example of contents of an access information storage area 106;

FIG. 8 is a diagram showing an example of the contents of an access information storage area 106.

9 is a diagram showing an example of the contents of an access information storage area 106. FIG.

FIG. 10 is a block diagram illustrating an example of a hardware configuration of a file access device.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 101 ... User program 102 ... Processing request control means 103 ... Simultaneous execution number setting means 104 ... Access method determination means 105 ... Processing execution control means 106 ... Access information storage area 107 ... Table control information 108 ... Batch access judgment information 109 ... Database File access means 110 ... Batch access means 111 ... Page unit access means 112-1 to 112-n ... Database file 114 ... Exclusive control means

Claims (6)

[Claims] An access method determining means for determining whether a data access request from a user program is a non-exclusive search request in a file access device for processing a data access request for a database file; An exclusive control means for exclusively controlling a data access request determined to be a request other than a non-exclusive search request by the access method determining means; a data access request permitted to be executed by the exclusive control means; and the access method determining means. An access unit for executing a data access request determined as a non-exclusive search request. 2. A file access apparatus for processing a data access request for requesting a batch access to data stored in a database file for a plurality of pages, wherein a plurality of pages of data from a user program are provided. Access method determining means for determining whether or not a data access request for requesting batch access is a non-exclusive search request; and determining that the data access request is a request other than the non-exclusive search request by the access method determining means. Exclusive control means for exclusively controlling the data access request, and access means for executing the data access request permitted to be executed by the exclusive control means and the data access request determined to be a non-exclusive search request by the access method determining means. And a file access device. 3. A file access apparatus for processing a data access request for requesting a batch access to data of a plurality of pages to a database file storing a plurality of tables composed of a plurality of pages. A concurrent execution number setting means for setting a collectively accessible upper limit number indicating an upper limit number of simultaneously collectively accessible tables requested by the collective access setting request from the user program; If the data access request for requesting batch access to the data of the page is for a certain table, if the batch access of the data access request is permitted, the user program becomes a target of the batch access. The number of tables to be accessed is set by the concurrent execution number setting means. Access method determining means for determining whether the data access request is a non-exclusive search request, and determining whether the data access request is a non-exclusive search request. An exclusive control unit for exclusive control of the data access request determined to be present; a data access request permitted to be executed by the exclusive control unit and determined by the access method determining unit not to exceed the collective accessible upper limit number; A collective access unit for executing a data access request that does not exceed the collective accessible upper limit number and is determined to be a non-exclusive search request by the access method determining unit; A data access request determined by the determining means to exceed the batch accessible maximum number, and the access method determining means File access device being characterized in that a page unit access means for executing been a data access request judged to be simultaneously accessible upper limit number, greater and no exclusive search request. 4. A recording medium recording a file access program for processing a data access request for a database file by a computer, wherein the data access request from a user program is a non-exclusive search request. Access method determining means for determining whether or not the data access request is a request other than a non-exclusive search request by the access method determining means; execution control is permitted by the exclusive control means And a file access program for functioning as an access unit for executing the data access request and the data access request determined to be a non-exclusive search request by the access method determination unit. 5. A recording medium on which is recorded a file access program for processing by a computer a data access request for requesting access to data stored in a database file for a plurality of pages at once. Access method determining means for determining whether or not a data access request from a user program requesting collective access to data for a plurality of pages is a non-exclusive search request; Exclusive control means for exclusive control of a data access request determined to be a request other than a non-exclusive search request by the exclusive control means, a data access request permitted to be executed by the exclusive control means, and a non-exclusive search request by the access method determining means. As an access means to execute the determined data access request File access program was recorded, machine-readable recording medium recording a program for causing ability. 6. A file access program for processing, by a computer, a data access request for requesting collective access to data of a plurality of pages to a database file storing a plurality of tables composed of a plurality of pages. A simultaneous execution number setting for setting the maximum number of batch accessibles indicating the upper limit of the number of tables that can be accessed simultaneously at the same time by setting the computer by a batch access setting request from a user program. Means, from the user program, when a data access request for requesting collective access to data for a plurality of pages is for a certain table, permitting batch access of the data access request; The number of tables targeted for batch access by the user program is An access method determining unit that determines whether or not the total number of batch accesses that can be set by the concurrent execution number setting unit is exceeded, and determines whether the data access request is a non-exclusive search request; Exclusive control means for exclusive control of a data access request determined by the access method determining means to be a request other than a non-exclusive search request, execution permitted by the exclusive control means and collective access upper limit by the access method determining means Batch access means for executing a data access request determined not to exceed the number and a data access request determined not to exceed the batch accessible upper limit number and to be a non-exclusive search request by said access method determination means, When the execution is permitted by the exclusive control means and the number of batch access is exceeded by the access method determining means, File access for functioning as a page-based access unit for executing a data access request that has been cut off and a data access request that exceeds the upper limit of batch access possible and is determined to be a non-exclusive search request by the access method determination unit. A machine-readable recording medium on which a program is recorded.