JPH01120647A - File managing system - Google Patents

Abstract

PURPOSE:To improve the file access efficiency and to omit a file recompiling process by attaining the addition, deletion, reference, updating, etc., of keys by means of an index table. CONSTITUTION:The record of an index table 21 stores the keys and a flag 24 showing the using condition of the record. At the same time, a record relative number 22 corresponds in 1:1 to a record relative number 26 of a data file 25. A file 28 is prepared for the table 21 for back-up in case of the discontinuation and the breakdown of a system. In case a data record having a key is added, an additional key is set with a relevant flag 24' set at 1 to back up the relevant record of the file 28 as long as no additional key is contained in the table 21. Then an idle record 27' of the file 25 is defined as a working record.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a file management system, and particularly to a file management system in a computer system equipped with disk files.

[Common technology]

Generally, the basic operating system of a general-purpose minicomputer manages three types of file management methods: sequential organization, relative organization, and indexed sequential organization. Among these, indexed sequential files enable record access using keys.

[Conventional technology]

Conventional file management systems use indexed sequential files for keyed record access.

- [Problem to be solved by the invention] In the indexed sequential file described above, when the number of additional records increases, an overflow area is created and key data is inserted, resulting in a significant drop in file access efficiency, and it is necessary to restore the efficiency. To do this, the disadvantage is that files must be reorganized periodically.

[Means for solving problems]

The file management method of the present invention includes the steps of: checking the existing record with a key to be added to the index table expanded on the main memory; searching for a record with a 0 flag in the index table; A step of setting the key to be added to the record, a step of setting the 0 flag of the above record to 1, and a step of adding the above record to the record of the index table/backup file in the relative organization format at the same record relative position as the relative position of the above record. A record addition process consisting of a step of backing up the contents, a step of making a record of a relative organization data file at the same record relative position as the record relative position of the above record a used record, and a process of deleting the record from the above index table. A step of searching for a record with a key, a step of clearing the key of the above record, a step of setting the flag of the above record to 0, and an index table in relative organization format at the same record relative position as the relative position of the above record. A record deletion process comprising the steps of backing up the contents of the record to a record of a backup file, and making a record of a data file in a relative organization format at the same record relative position as the record relative position as an empty record. , a record reference process consisting of a step of searching the index table for a record having a key to be referenced, and a step of reading a record of a relative organization format data file at the same record relative position as the relative position of the above record. and a record update process consisting of a step of searching for a record having the above record, and a step of updating a record of a relative organization format data file at the same record relative position as the relative position of the above record. .

〔Example〕

Next, one embodiment of the present invention will be described in detail with reference to the drawings.

FIG. 1 is a flowchart showing an example of record addition using the key of the present invention, FIG. 2 is a flowchart showing an example of record deletion using the key of the present invention, and FIG. 3 is a flowchart showing an example of record deletion using the key of the present invention. FIG. 4 is a flowchart showing an example of record reference; FIG. 4 is a flowchart showing an example of record updating using a key of the present invention; FIG. .

In the file management system of the present invention, in FIG. 1, an index table 21 shown in FIG.
Step 1 of checking the existing record with the key to be added to the index table 21
Step 2 of searching for the record 23' with flag 24', Step 3 of setting the key to be added to the record 23', Step 4 of setting the 0 flag 24' of the record to 1, and the relative position of the record. step 5 of backing up the contents of the record 23' to the record 23' of the index table backup file 28 in the relative organization format located at the same record relative position;
A record addition process consisting of step 6 in which the record 27' of the relative organization format data file 25 at the same record relative position as the above record relative position is made a use record; step 7 to search for a record with the key to be deleted; step 8 to clear the key of the record; and step 9 to set the flag of the record to 0.
and a step of backing up the contents of the above record to a record of the index table/backup file 28 in the relative organization format located at the same record relative position as the relative position of the above record; In FIG.
A record consisting of a step 12 of searching the index table 21 for a record having a key to be referenced, and a step 13 of reading a record of a relative organization format data file located at the same record relative position as the above record. In the reference process and FIG.
It consists of a step 14 in which the index table 21 is searched for a record having a key to be updated, and a step 15 in which a record in a relative organization format data file located at the same record relative position as the above record is updated. It consists of record update processing.

Next, the present invention will be explained in detail.

In FIG. 5, a record in the index table 21 includes a key and a flag 24 indicating the use status of the record.
is stored. When the flag 24 is 1, the corresponding record 23 stores the in-use key, and the flag 24' is 0.
When , the corresponding record 23' is an empty record.

Also, the record relative number 2 of the index table 21
2 has a one-to-one correspondence with the record relative number 26 of the data file 25. Note that the flag 24 also indicates the usage status of the record in the data file 25.
When flag 24' is 1, the corresponding record is the in-use record 27, and when flag 24' is 0, the corresponding record is empty record 27'. Index Chiful 21 has
An index table backup file 28 is prepared as a backup in case of system stop or system down. The index table backup file 28 is a relative organization data file having a structure similar to that of the index table 21.

Professional 0.0 that uses this index table 21 and data file 25. When Durham adds a data record with a key, it checks whether the additional key already exists in the index table 21, searches for a record in which the flag 24' of the index table 21 is 0, and obtains a free record 23'. . The obtained record is backed up to the corresponding record in the index table backup file 28 by setting an additional key and setting the corresponding flag 24' to 1. Thereafter, an empty record 27' of the data file 25 located at the same record relative position as the above record is made a used record.

When deleting a data record having a key, the index table 21 is searched using the deletion key to obtain the corresponding record 24. The obtained record is backed up to the corresponding record in the index table backup file 28 by clearing the deletion key and setting the corresponding flag 24 to 0. Thereafter, the used record 27 of the data file 25 located at the same record relative position as the above record is made an empty record.

When referring to a data record having a key, the index table 21 is searched using the reference key to obtain the corresponding record.

When updating a digital record having a key, the index table 21 is searched using the update key, and the corresponding record is obtained and updated.

〔Effect of the invention〕

The file management method of the present invention has the advantage that since keys can be added, deleted, referenced, and updated using an index table, file access efficiency is improved and file reorganization processing is not required.

[Brief explanation of the drawing]

FIG. 1 is a flowchart showing a first embodiment of the invention, FIG. 2 is a flowchart showing a second embodiment of the invention, and FIG. 3 is a flowchart showing a third embodiment of the invention. , FIG. 4 is a flowchart showing a fourth embodiment of the present invention, and FIG. 5 is a schematic diagram illustrating the structure of tables and files of the embodiment. 21... Index table, 22... Number indicating relative record number, 23.23', 23'...
・Key record, 24.24'...Flag, 25
. . . Data file in relative organization format, 26 . . . Number indicating relative record number, 27.27' . . . Record, 28 . . . Index table-backup file. Agent Patent Attorney Uchihara Otodai 1 Figure 2 $41! l

Claims (1)

[Scope of Claims] (A) A step of checking the existing record with a key to be added to the index table developed on the main memory, and a step of searching for a record with a 0 flag in the index table; A step of setting a key to be added to the above record, a step of setting the 0 flag of the above record to 1, and a step of setting the above record to the record of the relative organization format index table/backup file at the same record relative position as the above record. Record addition process (B) consisting of the step of backing up the contents of the above record, and the step of making the record of the relative organization format data file at the same record relative position as the record relative position as the use record (B) for the above index table. a step of searching for a record with the key to be deleted, a step of clearing the key of the above record, a step of setting the flag of the above record to 0, and a step of searching for the record with the key to be deleted. A record consisting of the step of backing up the contents of the above record to the record of the index table/backup file, and the step of making the record of the relative organization format data file at the same record relative position as the relative position of the above record an empty record. Deletion processing (C) consists of a step of searching the index table for a record having a reference key, and a step of reading a record of a data file in a relative organization format at the same record relative position as the relative position of the above record. (D) A step of searching the index table for a record having a key to be updated, and a step of updating a record of a data file in a relative organization format at the same record relative position as the relative position of the above record. A file management method characterized by including record update processing consisting of.