JPH02161541A - Divided storage processing system for indexed file - Google Patents

Abstract

PURPOSE:To independently execute the reedition processing of a record in each section by dividing an index part and a data part into plural sections having common identification (ID) numbers and expressing the records in both the areas by the deformation of their ID numbers and storage positions. CONSTITUTION:A user specifies a key range 4 and the space value of the area. A system side program (PG) allocates an area in each section to a volume in a direction access storage device 1 and registers correspondence between the key range 4 and a section number in a file control table 2. Then a record storage request having an optional key is generated from a user side PG. The system side PG executes the receiving processing of the request, determines the storage area and its address from the key value of the record based upon the key range information of correspondence information between the registered key range and the section number and stores the record. The key of the record and its pointer are registered based upon the key value of the record so as to be independently moved between areas as an indirect address due to deformation from the head of the data section.

Description

Detailed Description of the Invention [Field of Industrial Application] The present invention relates to a divided storage method for indexed files, and particularly to a divided storage method for indexed files in which the indexed files are stored in areas allocated on a direct access storage device. It is related to the method.

[Conventional technology]

Virtual memory access method (VSAM) is an access method that takes advantage of the features of virtual memory. There are three types of data sets that can be processed using VSAM: entry-ordered data sets, key-ordered data sets, and relative record data sets. Both are created on direct access storage devices (DASD) such as magnetic disk drives. The entry order data set is a data set in which records are stored in the order in which they are output, does not have an index, and has a data structure similar to the order data set and the direct data set. Therefore, it is a data set in which the records can be accessed in the order in which they are stored, or a specific record can be accessed by the storage address of the record. A keyed data set is a data set that has an index.

Records are stored in ascending order of keys and have indexes according to the order of keys. Therefore, the data set is such that it is possible to refer to the index and access in the order of the keys, or to access a specific record using the key. In addition, a relative record data set is a data set in which records are numbered relative to each other starting from 1, using the relative record number as a key.

This data set allows sequential access to records and direct access to specific records.

In this way, a VSAM key-sequenced data set has a structure in which records are stored in ascending order of keys, have indexes according to the order of keys, and can be accessed according to the keys. By the way, in a keyed data set,
There is a function called key range that divides one data set into multiple key ranges and stores records. With the key range function, records in the data section are divided and stored into areas according to the key range. The index is tree-structured data consisting of all key ranges, and
The data section has a structure divided into key ranges.

However, the data section is addressed by a displacement starting from 0 at the beginning of the data section area, and each divided area is not addressed independently.

FIG. 4 is a diagram showing a data structure when a data set is formed using the key range function.

In FIG. 4, 1 is a direct access storage device for storing record data, 2 is a file management list, and 3 is a file management record. The file management list 2 is a management table for managing a plurality of files, and a file management record 3 is provided in the file management list 2. The file management record 3 contains location information such as the volume where the file exists and the location of the file area on the volume.

Also, file attribute information such as file structure and record format is recorded for each file.

Using the key range function, records in the data section are divided and stored in each area according to the key range, so as shown in the figure, the file management record 3 contains the key range 4 for each area to be divided. Data specifying is set.

The data specifying the key range 4 is set by the user in advance using a service program. In a key-sequenced data set, a file area for storing file records is separately allocated on the direct access storage device 1, and an index section area 5 and a data section area 6 are provided. Area 5 of the index section stores index data of one piece of tree-structured data that manages the entire file. Furthermore, the area 6 of the data section is divided into a plurality of areas (area 1 to area n) divided by key range, and each record is stored according to each key range. Area 6 of the data section is divided into a plurality of areas based on key ranges, but area 5 of the index section is not divided into areas corresponding to key ranges to be set like the data section.

Between each area of the data part area 6, continuous addressing is provided with O being the beginning of the data part area. Therefore, if the data records of a certain key range cannot fit within the relevant area, a specific key range a-b is used, and each of the multiple areas storing records is made to correspond to the key range a-b. .

[Problem to be solved by the invention]

By the way, in systems that process large-capacity files such as databases, it takes a lot of time for file maintenance such as re-editing files.

For this reason, a large-capacity file is physically divided into a plurality of files, and file processing is performed for each divided file.

However, in such a file processing method, as the file capacity increases, the number of files further increases, and more time is required for file management. Furthermore, even when a file is constructed from a key-sequenced data set using the key range function as described above, the record storage area of the data section is divided and stored for each key range, but the index section for this is divided and stored. is a single tree-structured data, so when reorganizing each key range,
It is not possible to process the data part and index part in parallel at the same time, and each area of the data part is not addressed independently, so the size of the area corresponding to one key range is On the other hand, there is a problem in that it cannot be relocated on a direct access storage device.

The present invention has been made to solve the above problems.

SUMMARY OF THE INVENTION An object of the present invention is to provide a divided storage method for an indexed file that divides a large-capacity indexed file into a plurality of areas and enables records to be re-edited independently for each area.

The above and other objects and novel features of the present invention will become apparent from the description of this specification and the accompanying drawings.

[Means to solve the problem]

In order to achieve the above object, in the present invention, in a divided storage processing method in which an indexed file is stored in an area allocated on a direct access storage device, an index part and a data part of an indexed file are respectively divided into an index part and a data part. The records in the index part and the records in the data part are stored at addresses represented by the identification number and the displacement from the beginning of the area, and the records in the index part in each area are divided into multiple areas with common identification numbers. The record is made into tree-structured data independent of the records in the index section in other areas, and each record of the file is re-created and re-edited independently for each area.

[Effect]

According to the above means, the area of the index part and the area of the data part are divided into a plurality of areas having a common identification number, and the records in the area of the index part and the area of the data part indicate the area to which the record belongs. It is expressed by the identification number and the displacement from the beginning of the area to the position where the record is stored. The data in the index section has a file structure with independent tree structure data for each area.

As a result, the data section and index section in the file are divided into sections, and one section of the data section and the section of the index section corresponding to the data section of that section are associated with a common identification number. That will happen. Since the address of the record for each area is assigned independently for each area, even if the number of records in an intermediate area increases, the area can be expanded independently from other areas. Furthermore, the index data for each area is as follows.

This is because each area is treated as independent tree-structured data.

Record reorganization processing can be executed in parallel for each area. Therefore, the processing efficiency of batch processing for file maintenance can be improved.

Records within each area are addressed independently for each area, so even if the number of records in an intermediate area in the file increases, the area can be expanded.

Relocation on a direct access storage device is also possible for each area.

〔Example〕

Hereinafter, one embodiment of the present invention will be specifically described using the drawings.

FIG. 1 is a block diagram showing the configuration of main parts of a data processing device according to an embodiment of the present invention. In Figure 1,
7 is a central processing unit. The central processing unit 7 performs file processing, input/output activation, arithmetic processing, and the like. Also,
Reference numeral 1 denotes a direct access storage device, and as explained in FIG. provided. In this example, the area is divided into areas 1 to n, which have the same area number as area 5 of the index section and area 6 of the data section, and the records in each area are as follows.

Addressing is done by displacement with O as the beginning within each area. Therefore, records in each area will have addresses independent of records in other areas.

FIG. 2 is a diagram illustrating the data structure when indexed files are stored. In FIG. 2, 1 is a direct access storage device, 2 is a file management list, 3 is a file management record, 4 is a key range, 5 is an index area, and 6 is a data area. Further, 10 is a record as a recording unit. In each record 10 of the data section within each area.

A key 10a for identifying records is provided, and an index is created based on the value of the key 10a. In creating this index, an index is created using independent tree-structured data for each area of the index corresponding to the area of each data part. As shown in the figure, each area is set for each key range in accordance with the key range specified to divide the area of the file to be stored, and each area has an independent file structure. so that each area can become a processing unit that can be processed independently. That is, each area of area 6 of the data part and area 5 of the index part is set corresponding to key range 4, and one area of area 6 of the data part and one area of area 5 of the index part correspond. The file structure is such that records can be re-edited independently as one processing unit.

FIG. 3 is a flowchart showing a procedure for creating an indexed file according to an embodiment of the present invention. This will be explained with reference to FIG. In the indexed file creation procedure, the user specifies in advance the key range and the amount of space on the direct access storage device for the area corresponding to the key range,
Connect to the system. That is, in step 30, the user program specifies the key range and the amount of space in the area corresponding to the key range. On the other hand, in step 31, the system program allocates areas for each area to volumes on the direct access storage device.
In the next step 32, the correspondence between the key range and the area number is registered in the file management book.

Next, in step 33 from the user side program,
Issue a request to store a record with any key. In response to this, the system side program performs a record storage request acceptance process in step 34. Next, in step 35, based on the key range information of the correspondence information between the key range and the area number registered in the file management book, the area in which the record is to be stored is determined from the key value of the record requested to be stored. Next, in step 36, a storage address (displacement from the beginning of the area) within the determined area is determined, and the record is stored at the address within the area. Next, in step 37, the key of the record and the pointer to the record are registered in the index in the index area corresponding to the area of the data section based on the key value of the record. The pointer information at this time is an indirect address that only indicates the displacement from the beginning of the data area, so that the entire area can be moved independently between areas in response to processing. When the series of processes from step 35 to step 37 is completed, the process proceeds to the next step 38.

A process is performed to send a record storage process completion report to the user program, and the process for one keyed record storage request is completed. As a result, in the next step 39, the user side program issues a storage request for a record having an arbitrary primary key, and thereafter, the same processes as those in steps 34 to 38 are continued.

In this way, requests to store records with arbitrary keys are issued one after another, and correspondingly, record storage processing is performed one after another. As a result, by repeating the record storage processing procedure based on the user's request, a file having the data structure shown in FIGS. 1 and 2 is created.

In this way, 1. For example, as shown in the data structure of Figures 1 and 2, each area constituting a file has an independent file data structure, so each area can be , files can be created in parallel for each area, and files can be reorganized.

Even if the number of records in each area increases, since each area is addressed independently of other areas, the area can be expanded in each area to an address range that can be expressed by displacement. Furthermore, records can be restored by deleting only one area from the direct access storage device, reassigning that area to a different size on the direct access storage device, and relocating each area independently. becomes possible.

The present invention has been specifically explained above based on examples, but
It goes without saying that the present invention is not limited to the embodiments described above, and can be modified in various ways without departing from the spirit thereof.

〔Effect of the invention〕

As explained above, according to the present invention, even a large-capacity file with an index that has tree-structured data can be
The reorganization process can be performed in each area divided into a plurality of areas, and the reorganization process for each area can be performed in parallel at the same time.

Therefore, the processing efficiency of batch processing for file maintenance can be improved. Furthermore, records within each area are addressed independently for each area, so even if the number of records in the intermediate area increases in the file, the intermediate area can be expanded, and direct access storage for each area is also possible. Relocation above is also possible.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing the configuration of the main parts of a data processing device according to an embodiment of the present invention, FIG. 2 is a diagram illustrating the data structure when indexed files are stored, and FIG. FIG. 4 is a flowchart showing a procedure for creating an indexed file according to an embodiment of the present invention. FIG. 4 is a diagram showing a data structure when a data set is created using the key range function. In the figure, 1... direct access storage device, 2... file management list, 3... file management record, 4... key range, 5... index section area, 6... data section area. Area, 7...Central processing unit.

Claims (1)

[Claims] 1. In a split storage processing method that stores an indexed file in an area allocated on a direct access storage device, the index part and data part of the indexed file are divided into multiple groups each having a common identification number for the index part and the data part. Divide into areas, store records in the index part and records in the data part at addresses indicated by identification numbers and displacement from the beginning of the area, and store records in the index part in each area to the records in the index part in other areas. A split storage processing method for an indexed file, which is characterized in that tree-structured data is independent of records, and each record of the file is re-created and re-edited independently for each area.