JPH0371348A - High speed data access system - Google Patents

Abstract

PURPOSE:To efficiently obtain the latest data from file data by using different names for an exclusive resource name at the time of input for updating and an exclusive control resource name for reference. CONSTITUTION:By adding an identifier for updating at the time of updating processing 42, and adding an identifier for reference at the time of reference processing 43, they use an exclusive control management 45 as resource names, respectively. Accordingly, even if a store position is simultaneous data, updating and reference do not become exclusive control waiting, and in each processing, it is inputted from file data 27 of an external storage device 28 and can be stored in a buffer pool 44, and a simultaneous access can be efficiently realized. Also, in a control block for reference, a re-input instruction is recorded in advance when data is read out to the external storage device 28 by following the updating, by which when the same data is brought to access again by the reference processing 43, it is inputted from the file data 27 of the external storage device 28 and the latest data can be obtained without using the data stored in the buffer pool 44. In such a way, the latest data can be efficiently inputted.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to a data processing system, and when update and reference of file data conflict on the same data, the latest data is updated from the file without making the reference process wait as much as possible. The present invention relates to a high-speed data access method suitable for inputting data.

[Conventional technology]

In the conventional method, as described in Japanese Patent Application Laid-Open No. 61-269749-1, when a record update request occurs, blocks that have already been read into the buffer are invalidated, so that there is no inconsistency in file updates from multiple jobs updating simultaneously. It was a method.

Further, as described in Japanese Patent Application Laid-Open No. 145554/1983, the number of times of reference is stored in a memory, and data that is referenced less frequently is erased from the memory at the time of bulk update.

More common methods include an exclusive control method in which when an update and a reference conflict with the same data, one of them goes into a waiting state, or a method in which even if an update and a reference conflict, they can be accessed at the same time. - Once input from the file data of the external storage device, it is stored in the buffer pool of the main storage device, and when the same data is referenced repeatedly, the data is obtained from this buffer pool, or the data is input from the file data of the external storage device each time. The method was to do so.

[Problem to be solved by the invention]

In the above-mentioned conventional technology, the buffer is invalidated every time an update occurs, and at the same time, the update processing of another job that is accessed is also invalidated, and there is a problem in terms of an efficient access method for simultaneous processing.

Additionally, if you use a method that removes data that is referenced infrequently from A'1 during a batch update, or a method that accesses update and reference simultaneously and stores them in each buffer, the updated data will not be updated unless the reference data is deleted from the buffer. There was a problem with not being able to get it.

Furthermore, when there is a conflict between updating and referencing the same data,
4jl: If other control methods were used, access authority would be given to the preceding task, which would greatly depend on the data processing time of the preceding task, posing a problem in terms of processing efficiency.

An object of the present invention is to solve the above-mentioned problems in the conventional method by accessing the same data at the same time even when updating and referencing conflict with each other, and by accessing the same data at the same time when the updated data is flushed to an external storage device. The goal is to detect the latest data on the task side and input it from an external storage device, effectively utilize the buffer, reduce the number of input/outputs, and input the latest data.

[Means to solve the problem]

In order to achieve the above purpose, in a data processing system that accesses file data recorded in an external storage device, the exclusive quality layer name at the time of input for updating and the exclusive control resource name for reference are given different names. By doing this, it is possible to prevent waiting for exclusive control even though the record resources are the same.

In addition, in order to guarantee orderliness in the event that there is a conflict with references to the same data while the updated data is being flushed to an external storage device, the input/output status should be recorded in the control block that records the storage location of the accessed data. This is detected by reference processing to prevent double requests for rendering and reference, and is queued in the preceding purge completion queue. Thereafter, when the purge process is completed, the latest data can be obtained by taking out the reference request queued in the purge completion queue and inputting it from the file data in the external storage device.

! tJ, repeat the reference process for the same data before and after updating.
When executing 1j1, the data input in the previous reference process is passed and the latest data cannot be obtained, so when the updated data is finished being flushed out to the control block that has already recorded the input data, a re-input instruction is issued. By recording in the update task, even if the same data is referenced again, the buffer pool contents of the re-input instruction are discarded, and the latest data can be obtained from the file data on the external storage device. .

[Effect]

In a system where updating and referencing compete with each other for the same data recorded in an external storage device, the present invention provides information on the storage location of data in order to efficiently execute referencing processing and obtain the latest data. In addition to the information, an update identifier is added in the update process, and a reference identifier is added in the reference process, thereby using exclusive control management as the respective resource name.

As a result, even if the data is stored at the same time, updates and references do not have to wait for exclusive control, and in mutual processing, the data can be input from the file data on the external storage device and stored in the buffer pool, resulting in efficient simultaneous processing. Access can be achieved.

In addition, if a reference process occurs for the same data while it is being flushed to an external storage device for updating, the data storage location and input/output status are recorded in a control block provided for each data access unit, and the reference process is performed. It is possible to detect the input/output status of data at the same storage location when performing input processing for data processing, thereby preventing double requests for update and reference.

Furthermore, by recording the re-input instruction when updating the reference control block and flushing it to the external storage device,
When the same data is accessed again in the reference process, the latest data can be obtained by inputting from the file data of the external storage device without using the data stored in the buffer pool.

Through these operations, even if there is a conflict between updating and referencing the same data, the latest data can be efficiently input in the referencing process.

〔Example〕

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

FIG. 4 shows an example of the configuration of a data processing system to which the present invention is applied. In the figure, 41 is electronic calculation (
42 is a process for updating file data data; 43 is a process for referencing file data data; 44 is a data processing system that reads file data and stores it in the main storage device; When an access occurs, it determines whether to pass the read data in the buffer pool or re-read the latest data from the file data in the external storage device as it is updated, and performs exclusive control depending on the data access type. 45 is a process of checking the state of exclusive control mode corresponding to an exclusive resource and, if a conflict occurs, queuing the resource to be released according to the monid of the resource; 27 is a data record handled by the data processing system; An external storage device that stores these data records is called a database 28.

Figure 1 shows Rule 11, which requires unique resource names so that even if updates and references occur to the same data record, they are not treated as the same resource under exclusive control management. mode (shared mode)
Shared mode is a mode that allows peer access to resources. Exclusive mode: A mode in which only one task can access the same resource and no other task can access it. ) shows relation 12.

From this 11.12, the resource names are divided into those for updating and those for reference.
By using different modes depending on the type of data access, even if the same data is updated and referenced at the same time, both can be accessed.

FIG. 3 shows the overall management system when a data record is accessed 29 in each process, in which the update process side has a head pointer 21 of the accessed data record, and the reference process also has a similar pointer 22.

Furthermore, in order to efficiently manage each data record of file data, storage locations are organized into groups 26, and when a data record within this group is accessed, a data record control block 24 is registered in the corresponding group management table 23. By adopting such a management method, when an attempt is made to input reference IK (R31 in the process) while purging a data record Rat, the data record control block registered in the corresponding group management table is cleared, and the data record control block of the same data record is The input/output status is checked. As a result, if Ra L is in the process of cleaning, it is registered in the cleaning completion waiting queue 25 and access is temporarily given up. This access is resumed by the update task side when the cleaning of updated data is completed. The reference task is notified of the start of input.Then, the input process is restarted and the latest data can be input from the external storage device.

In FIG. 3, when data records are input in update and reference processing, respective buffer pool addresses are stored 35 in the data record control block.

Thereafter, when the data record R21°RLL is updated 33 on the update processing side, each record is updated only on the buffer pool, and when all update processing is completed, it is flushed out to file data in the external storage device.

When this sweep is completed, the control block of the data record that is H is searched for in the reference process, and the same data record R is searched.
a1. Record the re-input instruction in R, .

Then, the data record R1,l that has already been input in the reference process
When the data record is accessed again, the data record for the re-input instruction does not use the data stored in the buffer pool 32, but is input from the file data in the external storage device to obtain the latest data.

In this example, even if an update and a reference conflict on the same data, buffering between them can be avoided, and the latest data can be efficiently obtained from the file data.

〔Effect of the invention〕

According to the present invention, even if updating and referencing conflict with the same data in file data recorded in an external storage device, both can access the same data at the same time, and furthermore, the data records that are updated can be accessed simultaneously. is effective for efficient file data access because it is managed to obtain the latest data.

[Brief explanation of drawings]

Fig. 4 is an explanatory diagram of exclusive control management rules according to an embodiment of the present invention; Figs. 2 and 3 are explanatory diagrams showing a management method when data records are accessed from an external storage device; Configuration diagram of a data processing system to which the present invention is applied, No. 5
The figure shows processing flowchart 1-. 11... Exclusive resource name, 12... Exclusive control related table, 21-25... Access data record management method, 26-28... File data. 31-35... Management method for issuing re-input instructions. 4. Data processing system, 42. Update processing, 43. Reference processing. Ward Condolence 4 Guanhan Ward

Claims (1)

[Claims] 1. In a data processing system that accesses file data recorded in an external storage device, when data update and reference conflict for the same data, input processing for data update and input for data reference A high-speed data access method characterized in that the latest data can be input by inputting data from an external storage device without mutually exclusive waiting during processing.