JPH05120349A - Data base update managing system - Google Patents

Abstract

PURPOSE:To enable the non-stop operation of an on-line system for 24 hours. CONSTITUTION:When a data base retrieving instruction is issued, a retrieving means (not shown in the figure) retrieves a virtual data base 2 and when relevant data do not exist in the virtual data base, a real data base 3 is retrieved. When a data base updating instruction is issued, an updating means (not shown in the figure) stores updating data in the virtual data base 2. A reflecting means (not shown in the figure) fetches all the update history data in the virtual data base 2 in a cycle decided in advance, executes an update processing to the real data base 3 based on these update history data and erases the processed update history data from the virtual data base 2. Backup is executed by damping the contents of the real data base 3 to an MT in a cycle decided in advance.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a database update management system for online real-time processing.

[0002]

2. Description of the Related Art Conventionally, in online real-time processing, an updated latest database is always required. Therefore, every program searches and updates one real database, and backup processing stops online business. I went while I was there.

[0003]

The above-mentioned conventional database update management method has a drawback in that it is impossible to operate a 24-hour non-stop operation system because it is necessary to stop the online business in the backup process.

[0004]

A first invention comprises a virtual database for storing update history data and a real database for storing business data. When a database search command is issued, a search is performed from the virtual database. A search means for performing a search from the real database if the corresponding data does not exist in the virtual database, and an update means for storing the update data in the virtual database when a database update command is issued, And a reflection unit that deletes the processed update history data from the virtual database by taking all update history data in the virtual database in a given cycle and updating the real database based on the update history data. It is characterized by that.

A second aspect of the invention is characterized in that it has a backup means for extracting the contents of the real database to MT in a predetermined cycle.

[0006]

Embodiments of the present invention will now be described with reference to the drawings.

FIG. 1 is an explanatory diagram of update, search and backup processing according to an embodiment of the present invention.

It is composed of a program 1 for processing retrieval and update in real time, a virtual database 2 for storing update history, and a real database 3 for storing business data. Before updating by real-time processing, there is no data in the virtual database 2, and only the updated history is stored in the virtual database 2.

First, in the program 1, when a search command is issued, a search means (not shown) searches the virtual database 2 in the latest state. If the corresponding data does not exist in the virtual database,
The actual database 3 is searched, and the relevant data is loaded into the program 1.

Further, in the program 1, when an update command is issued, the update content is always stored in the virtual database 2 by the update means (not shown), that is, the latest data update content is stored in the virtual database 2. Although it is stored, the actual database 3 is not updated at this time. Therefore, even if the real database 3 is being processed in real time, backup processing using a magnetic tape or the like can be performed in parallel at any time.

FIG. 2 is an explanatory diagram of a process of reflecting the contents of the virtual database 2 on the real database 3 by the reflecting means (not shown). This shows a process of actually updating the contents of the virtual database 2 updated by the real-time process with respect to the real database 3. This process is
Since the real database 3 is not updated by the real-time processing, the virtual database 2 can be updated to the real database 3 at any time except during the backup process from the real database to the MT. In this reflection processing method, first, the history data of the virtual database 2 is fetched, then the real database 3 is updated based on the history data, and the processed history data is deleted from the virtual database 2. This is repeated until all the contents of the virtual database 2 are reflected. If an access conflict occurs between the real-time processing program 1 and the virtual database 2 during this reflection processing, exclusive control is performed in order to avoid data contradiction. Since this reflection processing can be performed at any time, it can be performed in a free cycle according to the business system, for example, every half day or every day. Further, the capacity of the virtual database 2 only needs to consider the amount of update data that occurs in the set one cycle, and the capacity of the virtual database 2 can be extremely small compared to the actual database 3, so the failure occurrence rate of the virtual database is extremely small. Become.

As described above, the backup process described with reference to FIG. 1 and the real database reflection process described with reference to FIG. . Further, even if a failure occurs in the real database 3, the real database 3 can be restored from the magnetic tape or the like in parallel with the real-time processing.

[0013]

As described above, according to the present invention, the virtual database and the real database are provided, the update history is stored in the virtual database, and the contents of the virtual database can be reflected in the real database in a free cycle. Will enable backup processing from the real database independently of online real-time processing.
There is an effect that the system can be operated without interruption for 24 hours.

[Brief description of drawings]

FIG. 1 is an explanatory diagram of update, search, and backup processing according to an embodiment of the present invention.

FIG. 2 is an explanatory diagram of a process of reflecting the contents of the virtual database 2 in the real database 3 of this embodiment.

[Explanation of symbols]

 1 program 2 virtual database 3 real database

Claims (2)

[Claims] 1. A virtual database for storing update history data and a real database for storing business data. When a database search command is issued, a search is performed from the virtual database and the corresponding data exists in the virtual database. If not, a search means for performing a search from the real database, an update means for storing update data in the virtual database when a database update command is issued, and an update in the virtual database at a predetermined cycle. A database update management system comprising: a reflection unit that takes in all history data, updates the real database based on the update history data, and deletes the processed update history data from the virtual database. . 2. The database update management system according to claim 1, further comprising a backup means for extracting the contents of the real database to MT in a predetermined cycle.