JPH0290341A - Saving system for data base file - Google Patents

Abstract

PURPOSE:To secure a back-up operation with no suppression of a transaction by detecting an interval of transactions or a back-up unit receiving no access and acquiring a partial back-up operation. CONSTITUTION:When the acquisition of the back-up is started, a transaction monitor means 4 decides to acquire the back-up of a schema (c) where no transaction access is carried out. Then a partial back-up acquiring means 5 starts the acquisition of the partial back-up. A transaction n2 is started and the instructions are produced from a data base control system 7 for update of both schemta (c) and (a). A back-up acquisition unit 3 informs the system 7 of the end of acquisition of the back-up when the acquisition of the back-up is through with the schema (c). Then a back-up correction means 6 carries out the back-up maintenance based on the data file update information 8. Thus all back-up operations are through.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a data processing system, and more particularly to a database file saving method for acquiring a backup of a database file.

[Conventional technology]

Traditionally, backups of database files are taken while no transactions are being executed, such as by stopping online, or
As described in Publication No. 48, the execution of transactions is suppressed.

[Problem to be solved by the invention]

The above-mentioned conventional technology does not take into account the continuous operation of the online system for 24 hours, and has the problem that backup cannot be obtained unless transactions are suppressed.

In addition, when attempting to take a backup of a database that is currently being updated using 1~Run Zakujion, it takes time to take the backup and modify the updated data that occurred during the backup, and a media failure may occur during the backup. There were problems such as the difficulty of taking countermeasures when an occurrence occurred.

The purpose of the present invention is to enable online access without stopping, and
An object of the present invention is to provide a database file saving method that obtains a partial backup of a backup acquisition unit that is not accessed by a transaction without suppressing transactions.

[Means to solve the problem]

In order to achieve the above purpose, in a data processing system that takes backups for database recovery in the event of a database failure, a first method that takes partial backups by detecting backup units that are not accessed or between transactions. a second means for recording data information updated from the start to the end of backup acquisition; and a third means for reflecting the updated data information recorded by the second means on the partial backup acquired by the first means. is set up to detect an interval in which no database or backup acquisition unit is being accessed, and to acquire a backup during this period so as not to stop online or suppress transactions.

[Effect]

The data processing system that performs backup acquisition creates a backup acquisition unit management table using a dictionary, etc., and based on this backup acquisition unit management table, backups that are not being accessed (referenced/updated) by the currently running transaction are Detects the acquisition unit and acquires a partial backup. If there is an access request from a transaction while a backup is being taken, the backup is stopped, transaction processing takes priority, and the backup is taken again.

After all the backups have been acquired, the data file update information from the transaction processing from the time when the backups were started is used to update the backups after all the backups have been acquired.

This allows you to create consistent backups without stopping online operations or suppressing transactions.

〔Example〕

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

FIG. 1 is a block diagram showing an example of a system configuration according to an embodiment of the present invention.

In FIG. 1, a backup acquisition data processing system 1 includes a backup acquisition unit management means 3, a transaction monitoring means 4, a partial backup acquisition means 5, and a backup modification means 6.

First, the user of the backup acquisition data processing system 1 specifies the start of backup acquisition and the unit of partial backup acquisition.

The backup acquisition unit management means 3 obtains information from the dictionary, as shown in FIG. 3, and creates the backup acquisition unit management table shown in FIG. 7.

Further, the backup acquisition unit management means 3 notifies the database management system (abbreviation: DBMS) 7 of the start of backup acquisition. From the time when the database management system 7 receives this notification, the database management system 7 sequentially accumulates the pig-based data update information as data file update information 8 in a memory or a secondary storage medium separately from the journal.

1-Crank John monitoring means 4 refers to the transaction management of the database management system 7, as shown in FIG. 4, and determines the backup acquisition units that are not referenced/updated by the running transaction, as shown in FIG. Locations to be backed up (tracks, records, databases, schemas, etc.) by searching from the backup acquisition completion time and resource ID in the backup acquisition unit management table
Determine.

The partial backup acquisition means 5, as shown in FIG.
A backup 2 of this determined location is obtained. During this period, if the database management system 7 makes an update request for the part that is being backed up, the database management system 7 notifies the transaction monitoring means 4 to that effect, and the partial backup acquisition means 5 receives the request from the transaction monitoring means 4. Cancel backup acquisition.

On the other hand, when the acquisition of a partial backup is completed, that fact is recorded in the backup acquisition unit management table.

The backup acquisition unit management means 3 checks whether or not the backup acquisition unit has been changed during backup acquisition, and corrects it if there is a change. The flow of this process is shown in FIG.

After the acquisition of all database backups is completed, a notification of completion of acquisition of all backups is issued to the database management system 7, and with this notification, the database management system 7 ends the accumulation of the data file update information 8.

The backup correction means 6 includes data file update information 8
Modify backup 2 using , and complete the bank up.

Generally speaking, the process of acquiring a backup of a database consisting of schemas a, b, and c will be explained with reference to FIG.

At the start of backup acquisition, the transaction monitoring means 4 decides to acquire a backup of schema C to which no 1-run transaction access has been performed, and the partial backup acquisition means 5 starts acquisition.

Transaction n2 starts, and a command to update schemas Q and a is issued by the database management system 7. This command stops the backup of schema C. At this time, there is no schema that can be backed up, so the state is in a waiting state. becomes. 1~Ranzakujiyon n
1 is completed and backup acquisition of schema b is started.

Next, transaction n2 ends and backup acquisition of schema a is started. When the backup acquisition of schema C is completed, the backup acquisition unit management means 3 notifies the database management system 7 of the completion of backup acquisition, and the backup modification means 6 executes backup maintenance using the data file update information 8. All backup acquisition is completed.

If data bus recovery becomes necessary due to a media failure or the like during backup acquisition, recovery is possible from the point at which all backup acquisition is completed.

In FIG. 2, if a medium failure occurs in schema a when a backup of schema C is taken, schema b is recovered using the pig file update information 8 after the backup of schema b is completed.

Therefore, instead of using all the backups of the previous generation, recovery is performed using partial backups for which backup acquisition has been completed, so the recovery time can be shortened. , it is possible to obtain backups without inhibiting the start of transactions or suppressing transactions.

Furthermore, when a failure occurs during backup acquisition, recovery is performed using the partial backup for which backup acquisition has been completed, resulting in an effect that the recovery time can be shortened.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing an example of a system configuration according to an embodiment of the present invention, FIG. 2 is a diagram for explaining the backup acquisition process of a database consisting of schemas a, b, and Q, and FIG.
4 is a flowchart showing an example of processing by the backup acquisition unit management means, FIG. 4 is a flowchart showing an example of processing by the ranzagion monitoring means, FIG. 5 is a flowchart showing an example of processing by the partial backup acquisition means, and FIG. 6 is a flowchart showing a processing example of the backup acquisition unit. FIG. 7 is a flowchart showing an example of processing in the case of an update request for a location that is being acquired. FIG. 7 is a diagram showing formats 1 to 7 of the backup acquisition unit management table. 1. Backup acquisition data processing system. 2 ・Back amplifier. 3. Backup acquisition management means. 4...1- Ranzaktion monitoring means. 5. Means for obtaining partial backup. 6... Backup modification means. 7 - Database management system A (DBMS). Data file update information. Tamezu 纂 苓 Ｇｕｒｕｎｔ Proceedings Amendment (Method) % Formula % Relationship with the case of the person who corrects the saving method of the database file Patent applicant name (510) Hitachi Ltd. (1!j-20,000) Agent ``Drawings'' to be amended Details of the amendment: Engraving of the drawings originally attached to the application, as shown in the attached sheet.

Claims (1)

[Claims] 1. In a data processing system that obtains a backup for restoring a database in the event of a database failure, a first method that detects between transactions or a backup unit that is not accessed and obtains a partial backup. means, a second means for recording data information updated from the start to the end of backup acquisition, and a third means for reflecting the updated data information recorded by the second means on the partial backup acquired by the first means. A database file backup method characterized by providing a means for backing up database files without stopping online or suppressing transactions. 2. The database file saving method according to claim 1, wherein the second means records the updated data information in a memory or a secondary storage medium.