JPH05204735A - Data management system - Google Patents

Abstract

PURPOSE:To execute real-time file retrieval at high speed and to eliminate the vacant areas for recording by storing the management information of files and the sort data of records on a main storage device. CONSTITUTION:Data management information is divided into a main storage device 2 and a magnetic disk device 3, data showing the existence of files of the data of file names, address data in the disk and file size data or the like are stored on the main storage device 2, and data showing the attributes of files required at the time of retrieving records of key information or the number of records or the like are provided at the head of files. According to the stored data, files are read and written. Thus, real-time file retrieval can be executed at high speed, the empty areas of records can be eliminated even in the case of erasing records, and flexible record retrieval is executed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a data management system using an auxiliary storage device, and more particularly to a data management system capable of reading and writing files in real time.

[0002]

2. Description of the Related Art As a data management system using an auxiliary storage device, there is, for example, the one disclosed in Japanese Patent Laid-Open No. 3-38741. Generally, a management area showing the location of a file is, for example, on a fixed disk. , And the record management area also exists on the file.

FIG. 6 is a diagram showing an example of a table in such a conventional data management system. (A) shows a file management area 101 for managing n files, and (b) shows a data section 102 that constitutes an actual file and an index section 103 necessary for key search.

FIG. 7 shows the structure of the index section 103 and the data section 102. Each index 1
A plurality of index entries are prepared in 04, and correspondingly, each record of each data 105 is stored for each predetermined length, and control information 106 for record management is stored in each.

When a file name is specified in the data management system provided with the above table, the file is searched from the file management area 101 and the file is read. Next, when searching for a record, a key is designated, the corresponding key is searched from the index 104, and the record pointed to by the index is found from the control information 106 and read. When a record is deleted, the area becomes an empty area as shown in FIG.

[0006]

The conventional data management system is configured as described above, and since the management information is on the auxiliary storage device, for example, on the disk, the management information on the disk is read once when the file is read. After that, it is necessary to search for the corresponding file, and it is not possible to perform high-speed real-time file search. In addition, there is a problem that an empty area of a record may occur when the record is deleted.

The present invention has been made in order to solve the above-mentioned problems, and it is possible to perform a high-speed real-time file search from the minimum necessary information and eliminate the empty area of a record. The aim is to provide a possible data management scheme.

[0008]

A data management system according to the present invention is a data management system for managing a plurality of files stored in an auxiliary storage device, and in the main storage device, data and address indicating the file name of each file are stored. A table area for storing data, size data and sort data of each record is provided, and a file is read and written from the stored data.

[0009]

In the data management system of the present invention, since the file management information and the record sort data are stored in the main storage device, the file can be searched with the minimum necessary information and the record can be deleted. You can eliminate the empty area after doing.

[0010]

1 is a system block diagram of a data management system according to an embodiment of the present invention. In the figure, 1 is a central processing unit, 2 is a main storage device, and 3 is a magnetic disk device provided as an auxiliary storage device.

FIG. 2 is a block diagram showing the structure of a table area provided on the main storage device 2. FIG. 2A shows the contents of the main table 4 and sub-table 5, and FIG.
Indicates the contents of each element in the sub-table 5. The main table 4 is provided with a header section 6 for registering data management keywords and a table address section 7 for storing the start address of the table for managing each file group, and the sub table 5 stores each file information. An area 8 for storing the number of elements for management, an area 9 for storing element length information, and an area 10 for storing each element are provided. Further, in each element 11, data representing a file name, a logical disk No (number), a sector address, file size data, the number of records, and the like are stored. Further, the table area is provided with a sort area for storing sort data of each record.

FIG. 3 shows the structure in a file stored in the magnetic disk device 3. As shown in (a), one file has a header part 12 and a data part 13.
The header section 12 stores the record length 14 of the records existing in the data section 13, the number of keys 15 and the key definition 16 necessary for performing the record search, and the data section 13 stores the record length. A record 17 having a length indicated by 14 is stored. Further, as shown in (b), the key definition, the key position, and the key length are stored as the key definition 16.

FIG. 4 shows the structure of an area used when performing a record search, which is provided with a sort area management unit 18 and the sort area 19 described above. Then, the records of the file read from the magnetic disk device 3 are sorted using the sort area 19 and the corresponding record is searched.
The use status of the sort area 19 is managed by using the sort area management unit 18.

Next, the operation will be described. In the data management system having the above-described configuration, a file on the magnetic disk device 3 in the computer system of FIG. 1 is searched at high speed, all records in the file are read and written, and a specified record is searched. If you delete a record, you can eliminate the open area of the record.

That is, when the online operation of the computer system is started, the data management information of FIG. 2 stored in the magnetic disk device 3 is transferred to the main storage device 2. Then, when a file data search instruction is issued through the central processing unit 1, the operation is executed as shown in the flowchart of FIG.

Here, first, it is shown in FIG. 2 which table address the corresponding file belongs to based on the designated file name.
From the main table 4 of (step S1). Then, the sub-table 5 of FIG. 2 is searched from the address indicated by the table address to know which element the file belongs to (step S2).

Next, the logical disk N of the file existing in the magnetic disk device 3 at the time when the element is found.
o, knowing the selector address and the file size, the corresponding file is read from the PUB address, selector address and file size in that element (step S3).

When searching for records when reading a file, records are sorted using the sort area 19 shown in FIG. 4 according to the key type, position and length of the key definition 16 shown in FIG. The corresponding record is searched (step S4). Then, after the record search, the file is written (step S5).

Next, it is checked whether or not the online operation is completed (step S6). If it is not completed, the above-mentioned file searching operation is repeated. Then, when the online ends, the information content of the data area management unit 18 of FIG. 4 is written in the magnetic disk device 3 (step S7). As a result, the latest data management information can be obtained at the start of the next online operation.

In the above management method, the data management information is divided into the main storage device 2 and the magnetic disk device 3, and the location of the file such as file name data, disk address data, and file size data is stored. Is stored in the main storage device 2, and the key information,
At the beginning of the file, data indicating the file attributes such as the number of records required for searching records is provided. Therefore, it is possible to perform a high-speed real-time file search, eliminate the empty area of the record even when the record is deleted, and perform a flexible record search.

[0021]

As described above, according to the present invention, the table area for storing the file name data of each file, the address data, the size data, and the sort data of each record is provided on the main storage device, and the table area is stored. Since the file is read and written from the stored data, it is possible to perform a high-speed real-time file search and eliminate the empty area of the record.

[Brief description of drawings]

FIG. 1 is a system configuration diagram of a data management system according to an embodiment of the present invention.

FIG. 2 is a block diagram showing the structure of a table area provided on the main storage device of FIG.

3 is a block diagram showing a structure in a file stored in the magnetic disk device of FIG. 1. FIG.

FIG. 4 is a block diagram showing a structure of an area used when performing a record search.

FIG. 5 is a flowchart showing the operation of the embodiment.

FIG. 6 is a block diagram showing a conventional example.

7 is a block diagram showing structures of an index part and a data part of FIG.

[Explanation of symbols]

 1 central processing unit 2 main storage unit 3 magnetic disk unit (auxiliary storage unit) 4 main table 5 sub table 7 table address section 19 sort area

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[Procedure amendment]

[Submission date] May 22, 1992

[Procedure Amendment 1]

[Document name to be amended] Statement

[Correction target item name] 0017

[Correction method] Change

[Correction content]

Next, the logical disk N of the file existing in the magnetic disk device 3 at the time when the element is found.
o, knowing the selector address and file size, the corresponding file is read from the logical disk name , selector address and file size in that element (step S3).

[Procedure Amendment 2]

[Document name to be corrected] Drawing

[Name of item to be corrected] Figure 2

[Correction method] Change

[Correction content]

[Fig. 2]

[Procedure 3]

[Document name to be corrected] Drawing

[Name of item to be corrected] Figure 5

[Correction method] Change

[Correction content]

[Figure 5]

Claims (1)

[Claims] 1. A data management system for managing a plurality of files stored in an auxiliary storage device, wherein data representing a file name of each file, address data, size data and sort data of each record are stored in a main storage device. A data management method characterized in that a table area is provided and a file is read and written from the stored data.