JPH0795302B2 - Database save device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Outline] The present invention relates to a database saving device that saves a database that has been subjected to an online processing operation after creation of an evacuation volume and has undergone an update processing to the evacuation volume again after the completion of the online operation. The number of the track that has undergone the update process is logged in the update track logging file, and after the online work is completed, only the track corresponding to the track number recorded in the above update track logging file is saved from the DASD above. The file is saved to a file, and then the part corresponding to the update track number in the save volume of the database is replaced with the content of the update track save file to create the latest save volume of the database.

[Industrial application field]

The present invention relates to a database saving device in an online system.

[Conventional technology]

An online system that uses a huge database, such as a banking system, performs online business during the day and suspends online business at night to perform incidental batch processing and database evacuation processing to a magnetic tape unit (MT). Is common.

The above-mentioned database saving process to MT is performed as a part of recovery measures at the time of failure, and in the online business, the database is updated with data before update and after update , Is recorded in a backout file (hereinafter referred to as BOF) and a history log file (hereinafter referred to as HLF), and after online work is completed, the database is sucked up by MT and a save volume is created.

If any abnormality occurs during the above update process, as is well known, the database at that point and the
Use BOF and HLF, or save volume on the previous day
Using HLF, the database can be restored to a normal state.

In this way, the BOF, HLF, and evacuation volume are always provided in order to minimize damage and enable accurate restoration when a failure occurs.

The database saving process is usually performed at night after the online work is completed. However, at night,
For system maintenance and other banking systems, automatic withdrawal of various charges and interest calculation are also performed, and all systems must be completed before the next day's business starts. As a result, there is little time to spare, and the operating hours of automated equipment such as automated teller machines (ATMs) are gradually extended, as has been the case these days.
As the time for online processing becomes longer, the night time becomes shorter and shorter, and it becomes difficult to save the database.

[Problems to be solved by the invention]

Conventionally, the contents of all databases are saved regardless of whether or not the data has been updated. Therefore, a certain amount of time is always consumed for the save processing, and when the data update is small, it results in unnecessarily occupying the data processing system.

It is an object of the present invention to provide a database saving device that can save the time required by obtaining the same effect as saving all databases by saving only the tracks that have been updated. It is in.

[Means for solving problems]

In order to achieve the above object, in the present invention, a series of processes for saving a database that has been subjected to an online processing operation after creation of an evacuation volume and has undergone an update process is saved to the evacuation volume again after the completion of the online processing operation ， Log the number of the track that received the update process in the update track logging file,
After completing the online work, save only the track corresponding to the track number recorded in the above update track logging file from the above DASD to the update track save file, and then add the above update track number in the save volume of the database. The relevant part is replaced with the contents of the update track save file to create the latest database save volume.

[Action]

Each time the database transferred to the above DASD is updated, the track number that has undergone the update process is logged, so all track numbers updated during online work are recorded in the update track logging file, By saving the contents of the above-mentioned update track on DASD at that time, the updated portion can be taken out without exception. Therefore, the contents of this saved track are used to rewrite the part corresponding to the saved track in the save volume before the start of online work, so that the same contents as the latest entire database on DASD are saved. You can get the volume.

〔Example〕

An embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 is a diagram showing the configuration of the above-described embodiment. Reference numeral 1 is the latest database save volume at the start of online processing work. This means that the database at the end of the previous work such as the previous day was saved.

Reference numeral 2 denotes a DASD, which is a storage device used for reading / writing data when executing business operations, and online processing operations such as deposit / withdrawal in a banking system are executed using the database on this DASD2. 21-24 show various states of the DASD.

Reference numeral 21 is the DASD state at the start of the online processing operation, and a ₁ and b ₁ are recorded in the database.

It is assumed that the data a ₁ is first updated to a ₂ [see DASD 22] and then the data b ₁ is updated to b ₂ [see DASD 23] to this database by the online processing operation 8.

Each time the above-described data update is performed, the update track logging program 12 stores the number of the track in which the updated data is stored, that is, the update track number 31, in the update track logging file 3. In the figure, the data a ₂ is stored in the track 1 and the data b ₂ is stored in the track 100.

When the online processing business 8 of the day is completed, the latest database is stored in the DASD 24. This database is evacuated by batch processing at night after the online processing is stopped. In this embodiment, the update track evacuation program 13 updates only the update tracks recorded in the update track logging file 3 to the update track evacuation file. Retreat to 4.

That is, as shown in the figure, the updated data a ₂ , b _2, ...
All the contents of the track in which is recorded, that is, the updated track 32 [the portion shown by the diagonal lines in the figure] is saved. In this operation, the update track save program 13 refers to the update track logging file 3 to check the update track number 31, reads the contents of the corresponding track, and writes this to the update track save file 4. Reference numeral 33 indicates the renewed updated track.

It should be noted that the drawing shows an example in which the update is performed only twice, but this is for convenience of description, and in reality, a large number of data are subjected to the update processing. Since a plurality of data are usually recorded on one track, the same track is often subjected to update processing a plurality of times.

In this way, even if one track is updated multiple times, DASD24
The latest state of all data is recorded in each track. Therefore, even if the same track is updated a plurality of times, if the track is saved once, all the data on the track can be saved.

Therefore, even if the same track number appears multiple times, it is sufficient to save each time only once. To do so, when saving the update track, first update the update track number 31 recorded in the update track logging file 3. Sorting and rearranging in the order of numbers are performed so that the tracks whose track numbers appear one or more times are saved once.

As a result, the database that has undergone the update processing has completed the minimum evacuation processing. That is, the latest state of the database can be obtained by matching the save volume 1 and the update track save file 4. Therefore, at the time of batch processing after the completion of the online processing work, it is sufficient to execute the processing up to this point, and it is preferable that the save volume 5 creation processing described below be executed all the time. In the case where there is no room, it is possible to use the updated track save file for processing when there is room at a later date, or it may be executed in a system different from the data processing system. it can.

Next, a method of creating the latest database save volume 5 from the update track save file 4 will be described.

The backup program 14 matches the update track save file 4 and the save volume 1 described above, and when the data of the same track exists in both, the contents of the save volume 1 are replaced by the contents of the update track save file 4 to create a new file. The evacuation volume 5 is obtained. In this operation, if the data of the same track is included in the update track save file 4 among the contents of the save volume 1, the data of the update track save file 4 is included. A new save volume 5 is created by saving the data.

With the above, the database saving process in this embodiment is completed. In the present embodiment, as described above, in the save processing performed concurrently with the batch processing subsequent to the online processing work, only the update track needs to be saved, and the updated data amount covers almost all the data in the database. Since there is almost no such data, and the amount is usually a fraction of the total data or less, the time required for the save processing is greatly shortened compared to saving all the data.

Even if the creation of the save volume 5 after this is performed at a later date,
Further, since it is possible to execute the processing in a system different from the data processing system, it becomes easy to perform batch processing in the system.

Since the new save volume 5 is in the latest DASD state, it can be used as original data at the time of recovery.

〔The invention's effect〕

As described above, in this embodiment, since only the update track is saved, the update time of the database can be shortened and the operation of the entire system becomes easy.

[Brief description of drawings]

FIG. 1 is a structural explanation of an embodiment of the present invention. In the figure, 1 and 5 are evacuation volumes, 2 is DASD, 3 is an update track logging file, 4 is an update track evacuation file, and 8 is an online processing operation.

Claims (1)

[Claims] 1. A backup volume (1, 5) for saving the contents of a direct access volume (2) for storing a database processed online, wherein the latest database at that time is stored prior to the start of online processing work. A database that is saved in the save volume (1), then performs online processing work, and creates a new save volume (5) with the same contents as the database on the direct access volume (2) after the online processing work is completed. In the evacuation device, an updated track logging file (3) that logs the number of the track that has been updated each time the database is updated in the online processing work, and the direct access volume (2) after the online processing work is completed. Said logged update track number An update track save file (4) for saving the contents of the corresponding track is provided, and when saving the database, the logged update track number of the contents of the save volume (1) before the start of the online processing operation is recorded. The database saving device is characterized in that a new saving volume (5) is created by replacing the part corresponding to the above with the contents of the update track saving file (4).