JPS63187347A - Data base file recovering system - Google Patents

Abstract

PURPOSE:To rapidly recover a data base file, by saving the data base file on the data base file for saving at every write of a prescribed quantity of image records after updating on a journal file. CONSTITUTION:At every write of the prescribed quantity of the image records after updating on the journal files 7-1 and 7-2, the data base file 8 is saved on the data base file 9 for saving. Therefore, when a fault is generated in the data base file 8, it is possible to recover the data base file 8 by using only the image record after updating accumulated in the journal files 7-1 and 7-2 after a time when the data base file 8 is saved most recently on the data base file 9 for saving. In such a way, it is possible to recover the data base file in a short time.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention is a data processing system that accesses database files that store various information, and when a failure occurs in the database file, the database file can be deleted in a short time. This invention relates to a database file recovery method that can be recovered.

[Conventional technology]

In data processing systems that access database files that store various types of information, in order to deal with failures in the database files, conventionally the database files are evacuated to backup database files every morning or every few days. At the same time, the updated image records after backup are accumulated in the journal file. If a failure occurs in the database file, the backup database file is first copied to the recovery database file, and then the updated image records are accumulated in the journal file. The recovery database file is recovered using all the after-update image records.

[Problem that the invention seeks to solve]

However, the conventional method described above periodically saves the database file to a backup database file, and if a failure occurs in the database file, an image of the entire database file at the time of backup is saved from the backup database file for recovery. Because the database file was copied to the database file and then the recovery database file was restored using all the updated image records stored in the journal file, a failure occurred a short time after the database file was evacuated. However, if the amount of after-image records in the journal file is small, file recovery can be performed in a short time, but
There was a problem that a failure occurred after a long period of time had passed, and it took a long time to recover the file if there were a large number of after-update image records in the journal file.

The present invention solves the above-mentioned problems, and its purpose is to enable recovery of database files in a short time.

[Means for solving problems]

In order to solve the above-mentioned problems, the present invention provides a database file that stores various information, a backup database file from which the entire database file is saved, and a recovery database file for restoring the database file. , and a journal file that stores updated image records when the database file is updated,
(al) an updated image record output processing unit that outputs an updated image record when updating the database file; a journal record writing processing unit that writes the updated image record output from the updated image record output processing unit into the journal file; , a detection processing unit that detects that the journal record writing processing unit has written a predetermined amount of updated image records to the journal file; a journal record including a frame record output processing unit that stores information indicating the accumulation position in the journal file of the updated image record accumulated in the journal file after the time when it is detected that the updated image record has been written to the journal file; an output means; (bl) a data file that saves the database file to the save database file every time the detection processing unit detects that a predetermined amount of updated image records have been written to the journal file; saving means; (0) database file recovery request receiving means for receiving a database file recovery request command requesting recovery of the database file; (11) database file recovery request receiving means for receiving the database file recovery request command; A database file copy processing unit that copies the save database file to the recovery database file; and a database file copy processing unit that copies the save database file to the recovery database file; and The database file recovery means includes a database file recovery processing unit that recovers a recovery database file.

[For production]

Every time a predetermined amount of updated image records are written to the journal file, the database file is saved to the save database file. Therefore, if a failure occurs in the database file, it is possible to restore the database file using only the after-image records accumulated in the journal file after the most recent backup of the database file to the backup database file. It becomes possible.

〔Example〕

Next, embodiments of the present invention will be described with reference to the drawings.

FIG. 1 is a block diagram of an embodiment of the present invention, in which journal record output means 1, means 2a for accepting initial setting commands, means 2b for accepting frame command requests,
A frame management table 3, a database file saving means 4, a database file restoring means 5, a database file restoring request structuring means 6, and a first. Second
It is composed of a journal file 7-1, 7-2, a database file 8, a backup database file 9, and a recovery database file 10. Further, the journal record output means 1 includes an updated image record output processing section 11, a journal file end detection processing section 12, and a journal record writing processing section 13.
and a frame record output processing section 14.

Further, the database file recovery means 5 includes a database file copy processing section 51 and a database file recovery processing section 52.

Next, a journal record output means 1, an initial setting command reception means 2a, a frame command request reception means 2b, a frame management table 3, a database file saving means 4, a database file recovery means 5, and a database file recovery request reception means 2a. The following describes the processing by means 6.

When the initial setting command receiving means 2a receives the initial setting command input by the operator, it notifies the frame record output processing section 14 of this fact.

When the frame record output processing unit 14 receives the notification from the means 2a to accept the initial setting command, the frame record output processing unit 14 stores an area N for storing the journal file serial number n, as shown in FIG.
, area M for storing frame number m and record number r
Write #l as the journal file serial number n in the area N of the frame management table 3 having the area R for storing , write #1 as the frame number m in the area M,
#0 is written in area R as record number r.

Further, upon receiving the above notification from the means 2a, the frame record output processing section 14 stores the database file 8 in the database file saving means 4.
to the backup database file 9, and write a file header label containing #1 as the journal file serial number n and a frame record containing #1 as the frame number m to the journal record writing processing unit 13. instruct. Upon receiving the above instruction, the database file saving means 4 saves the database file 8 to the saving database file 9, and the journal record writing processing unit 13 saves the database file 8 to the saving database file 9, and the journal record writing processing unit 13 saves the database file 8 to the first journal file 7-1 as shown in FIG. 1 to the file containing #1 as journal file serial number n and frame number m
Write a frame record containing #1 as .

The initial setting command is received by the means 2a, and after the above processing is performed and the information stored in the database file 8 is updated, the updated image in the journal record output means 1 is The record output processing unit 11 creates and outputs an updated image record corresponding to the updated content. The journal record write processing unit 13 writes area N of the frame management table 3.
If the journal file serial number n stored in is an odd number, the updated image record from the updated image record output processing unit 11 is written to the first journal file 7-1, In this case, the updated image record is written to the second journal file 7-2, and in this case, the journal file serial number n stored in area N is #.
1, the updated image record output processing unit 11
The updated image record from is written to the first journal file 7-1. Further, each time the journal record writing processing section 13 writes an updated journal record, it notifies the frame record output processing section 14 of this fact. When the frame record output processing section 14 receives the above notification from the journal record writing processing section 13, the frame record output processing section 14 increments the record number r stored in the area R of the frame management table 3 by one.

The above processing is performed every time the information stored in the database file 8 is updated, and the updated image record output processing unit 11 is output to the first journal file 7-1.
The updated image records created in are sequentially written, and the record number r stored in area R of the frame management table 3 is sequentially incremented by 1.

A journal file that accumulates journal records after updating? -1 and 7-2 are media such as magnetic disks and magnetic tapes, and since their capacity is limited, by performing the above processing every time the database file 8 is updated, the first Journal file 7- Naru.

The end of the first journal file 7-1 is detected by the journal file end detection processing unit 12,
The frame record output processing unit 14 is notified. When the frame record output processing unit 14 receives the above notification from the journal file end detection unit 12, the frame record output processing unit 14 increases the journal file serial number n stored in the area N of the frame management table 3 by 1 to #2, and stores it in the area M. The current frame number m is incremented by 1 to #2, and the record number r stored in area R is set to #O.

Furthermore, upon receiving the above notification from the journal file end detection processing section 12, the frame record output processing section 14 simultaneously outputs the data to the database file saving section 4.
Instructs the journal record writing processing unit 13 to save the database file 8 to the save database file 9, writes the file trailer to the first journal file 7-1, and includes #2 as the journal file serial number n. Instructs to write a frame record containing #2 as the file header Rahel and frame number %m to the second journal file 7-2. Upon receiving the above instruction, the database file saving means 4 saves the database file 8 to the saving database file 9, and the journal record writing processing unit 13 saves the database file 8 to the first journal file 7-1 as shown in FIG. A file trailer label is written, and a file header label containing #2 as the journal file serial number n and a frame record containing #2 as the frame number m are written in the second journal file 7-2 as shown in FIG.

Thereafter, each time the information stored in the database file 8 is updated, the updated image record output processing unit 11 outputs an updated image record corresponding to the updated content, and the journal record writing processing unit 13 outputs an updated image record corresponding to the updated content. In this case, since the journal file serial number n stored in area N of the frame management table 3 is #2, the updated image record from the updated image record output processing unit 11 is transferred to the second journal file 7-2. The frame record output processing unit 14 sequentially increments the record number r recorded in the area R of the frame management table 3 by 1.

When the frame command request framer 2b receives a frame command input by the operator while the updated image records are being stored in the second journal file 7-2 as described above, the following processing is performed. will be carried out.

Now, for example, suppose that the frame command request framing means 2b receives a frame command at the time when the process of writing the updated image record with record number r #i to the second journal file 7-2 is completed. The command request framer 2b notifies the frame record output processing unit 14 of this fact. Upon receiving the above notification, the frame record output processing unit 14 increments the frame number m recorded in the area M of the frame management table 3 by 1 to #3, and changes the record number r stored in the area R to #0. shall be.

Further, when the frame record output processing unit 14 receives the above notification from the frame command request arranging means 2b,
Instructs the database file saving means 4 to save the database file 8 to the saving database file 9, and also instructs the journal record writing processing unit 1
3 to write a frame record containing #3 as frame number m. Upon receiving the above instruction, the database file saving means 4 saves the database file 8 to the saving database file 9, and the journal record writing processing section 13 saves the database file 8 to the saving database file 9.
), a frame record including #3 as frame number m is written next to the updated image record with record number r #i.

Thereafter, each time the information stored in the database file 8 is updated, the updated image record output processing unit 11 outputs an updated image record corresponding to the updated content, and the journal record writing processing unit 13 outputs an updated image record corresponding to the updated content.
In this case, since the journal file serial number n stored in area N of the frame management table 3 is #2, the updated image record is output every time the updated image record is output from the updated image record output processing unit 11. The frame record output processing unit 14 sequentially writes the record number r stored in the area R of the frame management table 3 every time an updated image record is written to the journal file 7-2. +
Do 1.

While the updated image record output from the updated image record output processing unit 11 is being written to the second journal file 7-2 by the journal record writing processing unit 13, the journal file end detection processing unit 12 -2 is constantly detected as to whether the file has ended, and when the journal file end detection processing section 12 detects the end of the file, it notifies the frame record output processing section 14 to that effect. When the frame record output processing unit 14 receives the above notification,
The journal file serial number n stored in area N of frame management table 3 is increased by 1 to #3, and area M
The frame number m stored in area R is decreased by 1 to #4, and the record number r stored in area R is set to #0.

Furthermore, upon receiving the above notification from the journal file end detection processing section 12, the frame record output processing section 14 instructs the database file saving means 4 to save the database file 8 to the saving database file 9, and also The record writing processing unit 13 writes a file trailer label to the second journal file 7-2, and writes the frame record containing #3 as the journal file serial number n to the file containing #3 and the frame record containing #4 as the frame number m to the first journal. Instructs to write to file 7-1. Upon receiving the above instruction, the database file saving means 4 saves the database file 8 to the saving database file 9, and the journal record writing processing section 13 saves the database file 8 to the second journal file 7- as shown in FIG. 3(b). At the same time, as shown in FIG. 2, a file header label containing #3 as the journal file serial number n and a frame number m are written in the first journal file 7-1 as shown in FIG.
Write a frame record containing #4 as .

Thereafter, each time the database file 8 is updated, the journal file 7-
An updated image record corresponding to the updated content is written to 1, and the record number r stored in area R of the frame management table 3 is incremented by 1. For example, suppose that a failure occurs in the database file 8 at the time when the process of writing the updated image record with record number r #j to the first journal file 7-1 is completed (see FIG. 3(C)). reference).

When a failure occurs in the database file 8, the operator inputs a database file recovery request command to the database file recovery request means 6, and the database file recovery request acceptance means 6 sends the above request to the database file recovery means 5. Notice. When the above request is notified, the database file copy processing unit 51 in the database file recovery means 5 copies the save database file 9 to the recovery database file 10. In this case, when a frame record containing #4 is written as the frame number m to the first journal file 7-1, the database file 8 is saved to the backup database file 9, so the recovery database file 10 is saved. The content of is the same as the content of the database file 8 when a frame record including #4 as the frame number m is written to the first journal file 7-1. Therefore, in order to recover the recovery database file 10, a frame record including #4 as the frame number m is written to the first journal file 7-1, and then the frame record is written to the first journal file 7-1. It is sufficient to use only the updated image record. In addition, 1st. Second journal file 7-1.7-
Which of the updated image records stored in 2 is to be used depends on each area N, M of the frame management table 3.
.

This can be determined based on the journal file serial number n, frame number m, and record number r stored in R, and this processing is performed in the database file recovery processing section 52.

When the copy processing by the database file copy processing unit 51 is completed, the database file recovery processing unit 52 first copies the journal file serial number n, frame number m, and record stored in each area N, M, and R of the frame management table 3. Read number r.

At this time, the journal file serial number n stored in area N of the frame management table 3 is #3, the frame number m stored in area M is #4, and the number recorded in area R is 4.1.
The recorded record number r is #j. As described above, the journal file serial number n stored in the area N of the frame management table 3 specifies the journal files that store updated image records from the first journal file 7-1 to the second journal file 72.
〇 = 2 is incremented by 1 every time the number is changed to an even number, and each time the second journal file 7-2 is switched to the first journal file 7-1, it is incremented by 1 to become an odd number, so it is stored in area N. Depending on whether the serial number n of the journal file being used is an even number or an odd number, the post-update image record required when restoring the recovery database file 10 is the first journal file 7-
1, the second journal file 7
You can find out whether it is stored in -2.

Furthermore, the frame number m stored in the area M of the frame management table 3 is incremented by 1 each time a frame record including the frame number m is written to the journal file, and the frame number m stored in the area M of the frame management table 3 is incremented by 1 each time a frame record including the frame number m is written to the journal file. Since the file 8 is to be saved to the save database file 9, the area M
Based on the frame number m stored in the frame number m, it is possible to know the storage position in the journal file of the head portion of the updated image record, which is necessary when restoring the recovery database file 10.

Furthermore, the record number r stored in area R of the frame management table 3 is set to #0 every time a frame record is written to the journal file, and is incremented by 1 every time an updated image record is written to the journal file. Based on the record number r stored in the area R, it is possible to know the number of post-update image records required when restoring the restoration database file 10.

When the database file recovery processing unit 52 reads the contents of areas N, M, and R of the frame management table 3, it first checks whether the journal file serial number n stored in area N is an odd number or an even number. Therefore, the post-update image record required to restore the recovery database file 10 is the first. It is checked in which of the second journal files 7-], 7-2 the data is stored.

In this case, the journal file serial number n stored in area N is #3, which is an odd number, so the post-update image record required to restore the recovery database file 10 is the first journal file 7. −
You can see that it is stored in 1.

When it is learned based on the journal file serial number n that the updated image records required to restore the recovery database file 10 are stored in the first journal file 7-1, the database file recovery processing unit 52 recovers the recovery database file 10 by searching the first journal file 7-1 and finding a frame record containing the same frame number m as the frame number m stored in the area M of the frame management file 3. The leading position in the journal file 7-1 of the post-updated image record, which is required when performing the update, is found. In this case, area M of frame management table 3
#4 is stored as the frame number m, so the database file recovery processing unit 52
Processing is performed to search for a frame record containing #4 as frame number m from the journal file 7-1.

When the frame record including #4 is found as the frame number m, the database file recovery processing unit 52 updates the frame management table 3 stored in the area after the area where the found frame record is stored. Using the same number of updated image records as the value indicated by the record number r stored in area R, the contents of the recovery database file 10 are restored to the contents at the time of failure occurrence. In this case, since #j is written as the record number r in the area R of the frame management table 3, the j pieces stored in the part (a) shown in FIG. 3(c) are The post-update image record will be used to restore the restoration database file 10.

In this way, in this embodiment, when restoring the database file 8, data can be restored by using part of the updated image records stored in the journal files 7-1 and 7-2. Since the file 8 can be restored, the database file 8 can be quickly restored. Furthermore, in this embodiment, the frame command request is accepted by means 2b, and the database file 8 is saved to the save database file 9. Therefore, when the system load is light, the frame Database files can be restored more quickly by issuing commands.

In the above-described embodiment, the journal file end detection processing section 12 performs the first. Second journal file 7
- Every time a change is detected, the journal file that stores the updated image record is switched and the database file 8 is saved to the backup database file 9. However, the updated image record is stored in the journal file 7-1.7. The above process may be performed every time a predetermined amount is accumulated in -2. Furthermore, in the fifth embodiment described above, the first. Second journal file 7-
1゜7-2 was provided to store the updated image records alternately, but using - journal files, each time a predetermined amount of updated image records are accumulated, the updated image records are stored from the beginning of the journal file. It is also possible to accumulate records, and in this case, the area N for storing the journal file serial number n of the frame management table 3 can be omitted.

〔Effect of the invention〕

As explained above, the present invention saves a database file to a backup database file every time a predetermined amount of updated image records are written to a journal file, and when a failure occurs in the database file. , it is possible to restore the database file using only the after-image records accumulated in the journal file since the most recent time when the database file was saved to the backup database file, so the database file can be restored quickly. It has a restorative effect.

[Brief explanation of the drawing]

FIG. 1 is a block diagram of an embodiment of the present invention, FIG. 2 is a diagram showing the contents of the frame management table 3, and FIG. 3 is an explanatory diagram of the operation of FIG. 1. In the figure, 1...journal record output means, 2
a...Means for accepting initial setting commands, 2b...Means for accepting frame command requests, 3...Frame management table, 4...Means for saving database files,
5...Database file recovery means, 6...Database file recovery request highlighting means, 7-1.7-
2... Journal file, 8... Database file, 9... Backup database file, 10.
...Recovery database file, 11...Updated image record output processing unit, 12...Journal file end detection processing unit, 13...Journal record writing processing unit, 14...Frame record output processing unit, 51... database file copy processing section, 52.
...Database file recovery processing unit. 71. - Figure 1 shows the component liquid 1j of management table 3. Figure 1 shows the file label. 7-1 Digital file serial number I1 Frame record. (Frame number I1) Image code after update (I1) ■ ■ Yuneni '41J-: I -I L (b) 91 -1'''-゛Operation explanatory diagram of Fig. 1 Fig. 3 (Zonoko)

Claims (1)

[Claims] A database file storing various information, a backup database file in which the entire database file is saved, a recovery database file for restoring the database file, and a database file for updating the database file. A data processing system including: (a) an updated image record output processing unit that outputs an updated image record when the database file is updated; a journal record writing processing unit that writes the updated image record outputted from the output processing unit into the journal file; and a detection process that detects that the journal record writing processing unit has written a predetermined amount of updated image records to the journal file. and after the detection processing unit detects that a predetermined amount of updated image records have been most recently written to the journal file, the number of updated image records accumulated in the journal file after the time when the detection processing unit detects that a predetermined amount of updated image records have been most recently written to the journal file. (b) a predetermined amount of updated image records have been written to the journal file by the detection processing unit; (c) database file recovery request receiving means for accepting a database file recovery request command requesting recovery of the database file; (d) ) a database file copy processing unit that copies the save database file to the recovery database file by accepting the database file recovery request command with the database file recovery request receiving means; A database file recovery method comprising: a database file recovery unit that recovers the recovery database file using an updated image record corresponding to storage location information.