JPH01204161A - Exclusive control system - Google Patents

Abstract

PURPOSE:To improve an access multiplication degree by providing index counters in common and local areas respectively and deciding significant index information stored in a buffer when coincidence is obtained between both index counters. CONSTITUTION:When the coincidence is obtained between both values of the index counters 1-1 and 4-1 set in a common area 1 and a local area 2-1, the exclusive control is applied to the significant index information stored in a buffer 5-1 of the area 2-1 and the corresponding blocks of a data part 6-2 and a data file 7 and an access is given to a desired record. As a result, no queuing is produced at an index part 6-1 and the access multiplication degree is improved to the file 7.

Description

[Detailed Description of the Invention] [Summary] Regarding the exclusive control method when accessing a data file by referring to an index file, exclusive control is performed on a block-by-block basis without performing exclusive control on the index part of the index file. The purpose is to improve the multiplicity of accesses to files, and it is common to an index counter that stores a value such as +1 when the index section of an index file is updated or added to the local area, and a buffer that stores the contents of the index section. An index counter that stores a value such as +1 when the index part of an index file is updated or added is provided in the area, and when a program accesses a data file, it stores the value of the index counter in its own local area and the common area. When it is determined that the index counter value of , if it is determined that they do not match, the content newly read from the index section is stored in the buffer, and then this valid index information, the data section of the index file, and the corresponding block of the data file are exclusively controlled and the desired record is stored. Configure to access.

[Industrial application field]

The present invention provides an exclusive control method when accessing a data file by referring to an index file. Consider a database with the following structure. Generally, a record position to be accessed in the data file 22 is searched from the index file 21, and, for example, a desired value is read from the record at the corresponding position in the data file 22.

When multiple programs share and use such a database, exclusive control is required for each program.

To increase the degree of multiplicity used, block-based exclusive control is more effective than file-based exclusive control. However, as shown using diagonal lines in FIG. 3, for example, program
If block 4 is under exclusive control and the record in block 4 is being accessed, even if another program Y attempts to access another block in the data file 22, the index section 21-1 will wait for exclusive control. The problem is that the effect is almost the same as exclusive control on a file-by-file basis.

An object of the present invention is to improve the multiplicity of accesses to a data file by performing exclusive control on a block-by-block basis without performing exclusive control on the index portion of an index file.

[Means for solving problems]

Means for solving the problem will be explained with reference to FIG.

In FIG. 1, an index counter 1-1 and an index counter 4-i (i=1 to n) store values incremented by 1 when the index section 6-1 is updated or added, and are common. Area 1 or local area +
112-i.

The buffer 5-1 (i=1 to n) stores the contents of the index section 6-1.

The index file 6 includes an index section 6-1 containing search information in a tree structure, for example, and a data section 6-2 including a pointer pointing to the data file 7.

[Effect]

As shown in FIG. 1, the present invention does not exclusively control the index section 6-1 of the index file 6.
Every time it is accessed, for example, the program 3-1 in the local area 2-1 updates the value of the index counter 4-1 set in its own local area 2-1 and the value of the index counter 1-1 set in the common area 1. If they match, the index information stored in the buffer 5-1 is found to be significant, so this index information, the data part 6-2 of the index file 6, and the corresponding block of the data file 7 The desired record is accessed under exclusive control.

On the other hand, for example, in the local area 2-2, since there is no match, the contents of the buffer 5-2 are invalid, and the information read from the index section 6-1 of the index file 6 is stored in the buffer 5-2, and at the same time, the contents of the buffer 5-2 are invalid. After storing the value of the index counter 1-1 in the index counter 4-2 of the local area 2-2, this index information and the data section 6-2 of the index file 6,
A desired record is accessed by exclusive control of the corresponding block of the data file 7.

Therefore, no waiting occurs in the index section 6-1, and it is possible to improve the degree of access multiplicity.

〔Example〕

Next, the configuration diagram and operation of one embodiment of the present invention will be sequentially explained in detail using FIG.

In FIG. 1, the common area l is defined by the local area 2-i (
This area is commonly used by the programs 3-1 stored in i''l to n).

The index counter 1-1 is provided in the common area 1 and is used to determine whether the index information stored in the buffer 5-i of the local area 2-1 is significant. If they match, it is determined to be significant.

The local area 2-i is an area for storing programs 3-i and the like.

The program 3-i is an application program that refers to the index file 6 and accesses a desired record of the data file 7.

The index counter 4-i is for determining whether the index information stored in the buffers 5-i provided in the local area 2-4 is significant. The value stored in this index counter 4-i and the common area l
If the values stored in the in-def counter 1-1 provided in the two match, it is determined to be significant.

The buffer 5-i stores and holds index information read from the index section 6-1.

The index file 6 is composed of an index section 6-1 which is not subject to exclusive control, and a data section 6-2 which is subject to exclusive control.

Next, the operation when the index section 6-1 is updated or added will be described in detail in accordance with the order shown in FIG. Note that updates and additions to the index section 6-1 occur due to events such as expansion of the +11 index file 6 itself and (2) addition of a code with the maximum key value to the index file 6.

In FIG. 1, ■ in the figure indicates that the index counter 1-1.4-1 is increased by "+11" to "2" as shown in the figure in response to changes and additions to the contents of the block of the index section 6-i. represent. This means that when the program 3-1 changes or adds the contents of the index section 6-1, for example, adds a code with the maximum key value to a certain block, the index information of the buffer 5-1 is changed in response to this change or addition. This means that the index counter 4-1.1-1 is updated by "+1" to "2" as shown in the figure.

In the figure, ■ indicates that the values of the index counters 1-1 and 4-2 are compared and a mismatch (the contents of the buffer 5-2 are invalid) is detected. This is because when the program 3-2 attempts to access the data file 7, the index counter 1 provided in the common area 1 is used to determine whether or not the index information stored in the buffer 5-2 is significant as a preprocess. -1 value 12" and the value "1" of the index counter 4-2 provided in its own local area 2-2, and a mismatch (the contents of the buffer 5-2 are invalid) is detected. are doing.

3 in the figure performs invalidation processing for the index part buffer (buffer 5-2) of space 5 (this local area 2-2).

Then, in the next use, the latest index information is read from the index section 6-1 of the index file 6, stored in the buffer 5-2, and the index counter 4-2 of the common area l is read out. Store the value "2" of 1-1 to make them equal (.

As described above, instead of performing exclusive control on the index section 6-1 of the index file 6, the index counter 1-1 is placed in the common area 1 and the local area 2-i, respectively.
1.4-i is provided, and if both match, buffer 5-i is provided.
By determining that the index information stored in i is significant, the index unit 6-1 does not have to wait, making it possible to improve the multiplicity of accesses.

〔Effect of the invention〕

As explained above, according to the present invention, the index counter 1 provided in the common area 1 does not have exclusive control over the index section 6-1 of the index file 6.
-1 and significant index information stored in the buffer 5-4 of the local area 2-1 when both values stored in the index counter 4-i provided in the local area 2-1 match, Since the data section 6-2 and the corresponding block of the data file 7 are exclusively controlled and a desired record is accessed, there is no waiting in the index section 6-1, and the data file 7 is Access multiplicity can be improved. Furthermore, access speed can be improved by not performing exclusive control on the index section 6-1.

[Brief explanation of the drawing]

FIG. 1 is a block diagram of an embodiment of the present invention, FIG. 2 is a conceptual diagram of a database structure, and FIG. 3 is a diagram illustrating problems in the prior art. In the figure, 1 is a common area, 11, 4-i is an index counter, 2-1 is a local area, 3-i is a program, and 5-1
is a buffer, 6 is an index file, 6-1 is an index portion, 6-2 is a data portion, and 7 is a data file, where 1 represents an integer from 1 to n.

Claims (1)

[Claims] In an exclusive control method when accessing a data file by referring to an index file, a local area (2
-i) when the index section (6-1) of the index file (6) is updated or added, the index counter (4-i) that stores the value incremented by 1, etc. and the contents of the index section (6-1) are stored. Buffer to store (5-
i) and an index counter (1-1) that stores a value incremented by 1 when the index section (6-1) of the index file (6) is updated or added to the common area (1), and the program ( When 3-i) accesses the data file (7), it uses the value of the index counter (4-i) of its own local area (2-i) and the index counter (1-1) of the common area (1). If it is determined that the values match, the valid index information stored in the buffer (5-i), the data part (6-2) of the index file (6), and the corresponding block of the data file (7) access the desired record with exclusive control, while
If it is determined that they do not match, the index section (6-1
) is stored in the buffer (5-i), this valid index information, the data part (6-2) of the index file (6), and the corresponding block of the data file (7) are stored in the buffer (5-i). An exclusive control method characterized in that a desired record is accessed under exclusive control.