JPH03103943A - Save and restoration system - Google Patents

Abstract

PURPOSE:To prevent the increase of a save file capacity and the extension of the save processing time by performing the save processing with a page as the unit based on a journal file to prevent the increase of overhead for running of an application program. CONSTITUTION:A page number gathering means 2 reads in journal file 1 and gathers page numbers of pages, whose contents are updated, in the file on an auxiliary storage device 9 one by one based on contents of the file 1. A save processing means 8 reads in page images of pages corresponding to page numbers gathered by the page number gathering means 2 from the file on an auxiliary storage device 8 and saves read-in page images and page numbers in an increment file 6. Thus, the save processing for the same page is performed only once though the update processing of the same page is performed plural times, and the capacity of the save file is reduced and the restoration processing time is shortened.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an evacuation and restoration method for evacuation and restoration of files on an auxiliary storage device.

[Conventional technology]

If a file on the auxiliary storage device is saved on another medium and it becomes necessary to restore the file due to a file failure, etc., the file saved on the other medium can be used to restore the file on the auxiliary storage device. Restoring files has been practiced for a long time, and there are the following four conventional methods for saving and restoring files.

The first conventional method is to periodically or as needed save all data files on the auxiliary storage device to another medium, and when it becomes necessary to restore the files, save them to another medium. The files are restored by outputting all the data files that have been saved to the auxiliary storage device.

The second conventional method is to save all data files on the auxiliary storage device to another medium once, then save only the journal file that stores updated file contents, and then restore the files. If it becomes necessary, the file is restored on a record-by-record, page-by-page, or file-by-file basis. Restoration in units of records is performed by outputting all data files saved in separate media to the auxiliary storage device, reading update records from the journal file, and outputting the read update records to the auxiliary storage device. Page-by-page or file-by-file restoration is performed by outputting all data files that have been evacuated to another medium to the auxiliary storage device, and then performing page image or update after updating pages that have been updated based on all data files and journal files. This is done by creating an updated file image of the updated file and outputting the updated page image or file image to the auxiliary storage device.

The third conventional method is to save all data files on the auxiliary storage device once to another medium/body, then save the updated files file by file to another medium, and then restore the files. In this case, the file is restored by outputting all the data files saved in a separate medium to the auxiliary storage device, and then outputting the saved updated file image to the auxiliary storage device.

The fourth conventional method is to save all data files on the auxiliary storage device once to another medium, and then collect updated page information each time the data file is updated, periodically or as needed. Only pages that have been updated based on updated page information that has been saved are saved page by page to a separate medium, and if files need to be restored, all data files saved to the separate medium are saved to the auxiliary storage device. After outputting to
The file is restored by outputting the saved updated page image to the auxiliary storage device.

[Problem to be solved by the invention]

Each of the conventional methods described above has the following drawbacks.

In the first conventional method, all data files are saved to a separate medium periodically or as needed, which has the disadvantage that the capacity of the save file and the save processing time become enormous.

The second conventional method saves only the journal file after all data files have been saved once, so the capacity of the save file and the save processing time can be reduced compared to the first conventional method. However, when restoring in units of records, it is necessary to perform the restoration process the same number of times as the number of updated records, and when restoring in units of pages or files, it is necessary to restore from all data files and journal files that have been evacuated. This method requires processing to create an updated page image of an updated page or a file image of an updated file, which has the drawback of lengthening the restoration processing time.

In the third conventional method, updated files are saved in file units, so pages that have not been updated are also saved, resulting in a problem that the capacity of the saved file becomes unnecessarily large.

The fourth conventional method saves updated pages page by page, so the size of the save file can be smaller compared to the third conventional method, but the process of collecting updated page information is based on data files that are updated. Since the process is executed every time the program is executed, there is a drawback that the overhead during the running of the business program becomes large.

SUMMARY OF THE INVENTION An object of the present invention is to reduce the capacity of a save file and shorten the restoration processing time without increasing the overhead when running a business program.

[Means to solve the problem]

In order to achieve the above object, the present invention provides an auxiliary storage device in which files are stored, a storage medium from which all files stored in the auxiliary storage device are saved as save files, and a storage medium in which the files are saved in the storage medium. In a system equipped with a journal file in which updated contents of the file are sequentially accumulated after being evacuated, an incremental file is provided in the storage medium, and the journal file is read and the auxiliary storage is updated based on the contents. A page number collection means for collecting page numbers of updated pages in a file on the device, one for each updated page, and a page image of the page corresponding to the page number collected by the page number collection means. a saving processing means that reads the page image from a file on the auxiliary storage device, associates the read page image with its page number, and saves it to the incremental file, and after restoring all the saved files onto the auxiliary storage device, The incremental file is read backwards from the end to the beginning, and only when an unprocessed page number is read, the page image saved in the incremental file corresponding to that page number is stored on the auxiliary storage device. A restoration processing means for restoration is provided.

[For production]

The page number collection means reads the journal file,
Based on the contents, the page numbers of the updated pages in the file on the auxiliary storage device are collected one by one for each updated page.

The saving processing means saves the page image of the page corresponding to the page number collected by the page number collecting means into the auxiliary storage.
Read from the second file and save the read page image and its page number to an incremental file. Therefore, even if the update process for the same page is performed multiple times, the save process for the same page is only performed once, making it possible to prevent increases in file capacity and save process time. After restoring all saved files to the auxiliary storage device, the restoration processing means reads the incremental files backwards from the end to the beginning, and only when an unprocessed page number is read, the incremental file corresponding to that page number is restored. Restore the page image saved on the auxiliary storage device. Here, since the restoration processing means reversely reads the incremental file, the evacuation processing by the page number collection means and the evacuation processing means is performed multiple times, and the incremental file 6
If there are a plurality of page numbers and page images of the same page, the page image saved in another medium corresponding to the unprocessed page number indicates the latest updated image of that page. Therefore, by performing the restoration process only when an unprocessed page number is read, that is, by performing the restoration process ■ times for the same page, the corresponding page on the auxiliary storage device is restored to the latest updated image. can do.

〔Example〕

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

FIG. 1 is a block diagram of an embodiment of the present invention, including a journal file 1, page number collection means 2, save processing means 3, restoration processing means 4, human output processing 5, and incremental file 6. , an evacuation medium 8 in which all evacuation files 7 are stored, and an auxiliary storage device 9. In this figure, solid line arrows indicate the flow of data during the save process, and broken line arrows indicate the flow of data during the restore process.

The page number collecting means 2 has a function of reading an update record from the journal file 1 and adding the page number of the updated page obtained based on the contents to the save processing stage 3. The save processing 1000-stage 3 passes the page number passed from the page number collection 1000-stage 2 to the input/output processing 1000-stage 5, reads the page image of the corresponding page from the auxiliary storage device 9, and saves the read page image and its page number. It has a function of writing one page of information to the incremental file 6. The restoration process 1,000 steps 4 reads the entire saved file 7 and outputs it to the auxiliary storage device 9 using the human output process 5, and reads the incremental file 6 backwards from the end to the beginning. If the page number is an unprocessed page number, it has a function of outputting the page image written in the incremental file 6 corresponding to that page number to the auxiliary storage device 9 using the human output processing means 5.

FIG. 2 is a flowchart showing an example of processing for page number collection 1000 stages 2,
FIG. 3 is a flowchart showing an example of processing by the save processing means 3, and FIG. 4 is a flowchart showing an example of processing by the restoration processing means 4. The operation of this embodiment will be described below with reference to each figure.

First, the saving process will be explained with reference to FIGS. 1, 2, and 3.

In FIG. 2, the page number collecting means 2 performs processing step 2.
1 reads one update record from journal file 1. In processing step 22, it is determined whether the file END of journal file 1 has been reached, and the file END is determined.
If it is determined that the file has reached END, processing step 26, which will be described later, is executed, and if it is determined that the file is not END, processing step 23 is executed. In the processing step 23, based on the update 11 new record read from the journal file 1 in the processing step 2l, the page number of the page containing the updated record is searched. Here, since information indicating the page number is included in the update image of the update record, the page number search can be realized by extracting the information.

In the next processing step 24, it is checked whether or not the page number retrieved in the processing step 23 is registered in a save page number table (not shown) provided inside the page number collection means 2. If so, process step 21 is executed again, and if it is not registered, process step 25 is executed, and then process step 21 is executed again. Here, the evacuation page number table is a table for arranging and storing page numbers in ascending order, and even if there are n update records for the same page in the journal file 1, It is used to save to the incremental file 6 only once. In processing step 25, the page numbers retrieved in processing step 23 are registered in the evacuation page number table in ascending order.

12 Then, when the above-mentioned process is performed up to the file END of journal file 1 (the judgment result of the processing step 22 is yes), the page number collecting means 2 saves the page numbers of the updated pages in ascending order. Sends the contents of the table to the save processing means 3 (processing step 2
6) The process will be completed this winter.

When the save processing means 3 receives the contents of the save page number table from the page number collection 1000 stage 2, it starts the process shown in the flowchart of FIG. Extract one page number from the contents of the number table. In the next processing step 32, it is checked whether all the page numbers registered in the evacuation page number table have been extracted. If it is determined that all the page numbers have been extracted, the process is terminated, and if it is determined that they have not been extracted, the processing step is executed. Execute 33. The processing step 33 sends the page number retrieved in the processing step 31 to the human output processing means 5, and the input/output processing means 5 generates a page image corresponding to the page number retrieved from the auxiliary storage device 9 based on the page number. receive. In the next processing step 34, the page number taken out in the processing step 31 and the page image received in the processing step 33 are outputted to the incremental file 6 in correspondence, and again in the processing step 31.
Execute.

As explained above, in the saving process, the page number collecting means 2 collects the page number of the updated page from the journal file l, and the saving processing means 3 uses the human output processing means 5 to generate a page image of the page number. Auxiliary memory W
9 and outputs the extracted page image to the incremental file 6.

Next, the restoration process will be explained with reference to FIGS. 1 and 4.

In FIG. 4, the restoration processing means 4 first reads all saved files 7 from the saved medium 8 in processing step 41, and outputs the read all saved files 7 to the auxiliary storage device 9 using the input/output processing means 5. .

At this stage, the data files in the auxiliary storage device 9 are restored to the image at the time when all files were saved periodically or at an appropriate time. In the next processing step 42, the incremental file 6
is read backwards by one page from the end to the beginning to obtain the page number and page image.

In the next processing step 43, it is determined whether all page numbers and page images stored in the incremental file 6 have been read, and if it is determined that all have been read, the process is terminated, and it is determined that they have not been read. If so, the processing step 44 is executed. In the processing step 44, it is determined whether or not the page corresponding to the page number read in the processing step 42 has already been restored. Check by referring to a number table (not shown). If it is determined in processing step 44 that the data has already been restored, processing step 42 is executed again, and if it is determined that restoration has not yet been completed, processing step 45 is performed. In processing step 45, first, the page number and page image read from incremental file 6 in processing step 4152 are sent to human output processing stage 5.

When the page number and page image are added from the restoration processing means 4, the input/output processing stage 5 writes the page image added from the restoration processing means 4 to the page corresponding to the page number on the auxiliary storage device 9. Therefore, at this stage, the page corresponding to the above page number on the auxiliary storage device 9 has been restored to the latest updated image. Further, in processing step 45, the restoration processing 1000 steps 4 registers the page numbers read by the processing stepper 42 in the restoration page number table in ascending order, and executes processing step 42 again.

Here, the reason why the incremental file 6 is read backwards in processing step 42 and the restoration process (processing step 45) is performed only on the pages determined to be unprocessed in processing step 44 is as follows. .

That is, after all files are saved to the all save file 7,
Assuming that the same page has been updated n times, the page number and page image of the same page 16 have been output to the incremental file 6 at least once and at most n times. The number of times the page number and page image of the same page are output is affected by the number of times the save process (the process shown in Figures 2 and 3) is performed, and the save process to incremental file 6 is performed only once after saving all files. If not, the same page will be output to the incremental file 6 once, but if the save process to the incremental file 6 has been performed n times after saving all files, each save process will output the same page to the incremental file 6 once. Since there is a possibility that the page number and page image have been output to the incremental file 6, the number of times the same page is output to the incremental file 6 is n times at most. In this way, the incremental file 6 may store multiple page numbers and page images of the same page, but as described above, the incremental file 6 is read backwards and the restoration process is performed only for unprocessed pages. By doing this, 1 for the same page
This is because the corresponding page on the auxiliary storage device 9 can be restored to the latest updated image just by performing the restoration process once, and the restoration processing time can be shortened.

As explained above, the restoration process is performed by outputting all the saved files 7 read by the restoration processing means 4 to the auxiliary storage device 9 using the human output processing means 5, and then reading the incremental files 6 backwards. This is realized by similarly outputting the updated image to the auxiliary storage device 9 using the input/output processing means 5.

〔Effect of the invention〕

As described above, since the present invention performs the saving process based on the journal file, there is an effect that the overflow during running of the business program is not increased. Furthermore, in the present invention, even if there is multiple update information for the same page in the same journal file, the same page is saved only once.
This also has the effect of preventing an increase in the backup file size and backup processing time. Furthermore, since the present invention performs the restoration process on the same page only once for each page, it also has the effect of shortening the restoration process time.

[Brief explanation of drawings]

FIG. 1 is a flowchart of an embodiment of the present invention, FIG. 2 is a flowchart showing an example of the processing of the page number collection means 2, FIG. 3 is a flowchart showing an example of the processing of the evacuation process 3, 5 is a flowchart showing an example of processing by the restoration processing means 4. FIG. In the figure, 1... journal file, 2... page number collection means, 3... saving processing means, 4... restoring processing means, 5... input/output processing means, 6... Incremental file, 7... All save files, 8... Save medium,
9... Auxiliary storage device.

Claims (1)

[Claims] An auxiliary storage device in which files are stored, a storage medium from which all files stored in the auxiliary storage device are evacuated as all evacuated files, and a storage medium after the files are evacuated to the storage medium. In a system equipped with a journal file in which updated contents of the file are sequentially accumulated, an incremental file is provided in the storage medium, and the journal file is read and the contents of the file on the auxiliary storage device are updated based on the contents of the journal file. a page number collection means for collecting page numbers of updated pages one by one for each updated page; and a page number collection means for collecting page numbers of pages corresponding to the page numbers collected by the page number collection means, and storing the page image of the page corresponding to the page number collected by the page number collection means in the auxiliary storage device. a saving processing means that reads from the above file, associates the read page image with its page number, and saves it to the incremental file; and after restoring all the saved files onto the auxiliary storage device, terminates the incremental file. restoration processing means that reads backwards from the beginning toward the starting end, and restores the page image saved in the incremental file corresponding to the page number onto the auxiliary storage device only when an unprocessed page number is read; An evacuation and restoration method characterized by providing the following.