JPH05100935A - Data base managing system - Google Patents

Abstract

PURPOSE:To automatically execute a dynamic saving processing of a data base system, whenever an updating processing of a prescribed quantity is executed to a data base file. CONSTITUTION:In the data base system, this system is provided with an input/ output means 2A for executing an input/output processing of a data base file, a journal control means 2B for executing output control of the updated data base file, and a file saving means 2C for executing a saving processing without suspending the operation of the data base file, from which the upper limit is provided in the data quantity of a data journal file 4 after the data base file 3 is updated, and whenever an updating processing of a prescribed quantity is executed, a dynamic saving processing of the data base system is executed automatically. The saving processing of the data base file can be automatized. Also, when abnormality is generated, since a new saving file is always prepared in advance, a release processing can be executed quickly.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a database management system, and more particularly to collecting a journal and database file save data for database recovery processing when an abnormality occurs during operation of a database system operated by an electronic computer. The present invention relates to a database management method that enables automatic control.

[0002]

2. Description of the Related Art In a database system operated by an electronic computer, as shown in FIG. 2, an operator activates a file save program 7 at regular intervals in preparation for an abnormality in the database file 3 to make the database file 3 available. Data is saved in the save file 6 of the magnetic tape, and the database controller 2 outputs the update history information for the database file 3 after the data save to the journal file 4 (during the file save operation, Application program 1
May need to stop the operation of). When an abnormality actually occurs, the operator saves the saved data in the save file 6 back to the database file 3, and based on this, the update processing performed immediately before the abnormality occurs is performed in the journal file 4. The restoration work is performed by the method of reflecting the state of the database file 3 to the state immediately before the occurrence of the abnormality by reflecting the update history information collected in the above.

[0003]

It is necessary for the operator to manage the file saving process for restoration using the update history information, and if the saved data used for restoration is old, the update history information will be updated from the time of saving. Since it is necessary to collect the information of the above, it will take a huge amount of journals and it will take a long time to recover.Therefore, the files are saved regularly, the contents of the saved data are made newer, and the update history information is It was necessary to consider to keep it as low as possible. Therefore, an object of the present invention is to simplify the operation of the database system by automating the management of the database file saving process.

[0004]

The database management system of the present invention is, in a database system operated on an electronic computer system, an input / output unit for performing input / output processing of a database file, and a data journal after updating the database file. A journal control unit that controls output of a file and a file saving unit that dynamically executes a saving process without interrupting the operation of the database file are provided, and the data saving unit updates the data journal after updating the database file. It is configured by setting an upper limit on the amount of data in a file and automatically performing dynamic save processing of the database system every time a certain amount of update processing is executed.

[0005]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to FIGS. 1 and 3 to 10. Here, the operation during normal operation of the database and the operation during execution of the save process are shown.

[0006] During operation of the database system, a database file 3, a journal file 4 for recording update information for the database file, a working file 5 for storing a journal at the time of file saving, and a content of the database file are stored. Prepare the save file 6 and
Normally, the user is AP (application program) 1
In accordance with the instruction, the database control unit 2 refers to and updates the database file 3, and stores the update information in the journal file 4. And
Every time a certain amount of update history information is accumulated in the journal file 4, the contents of the database file 3 are placed in the save file 6 so that the contents of the journal file 4 up to that point are unnecessary and new update history information is added. Start accumulating. As a result, if any abnormality occurs in the database file 3 during system operation, the data of the save file 6 is stored in the database file 3 and then the update history information of the journal file 4 is reflected to make the database file 3 It is possible to restore the contents of to the state just before the occurrence of the file abnormality and continue the operation of the database system from there.

Of the block diagram showing the configuration of the embodiment of the present invention shown in FIG. 1, the configuration of the embodiment at the time of normal operation of the database and at the time of file saving processing is shown in FIGS. 3 and 4, respectively. A flow chart of the input / output processing at this time is shown in FIG. 5, a flow chart of the journal control processing called from the input / output processing is shown in FIG. 6, and a flow chart of the file saving processing is shown in FIG.

As shown in FIG. 5, in the input / output processing, first, the database processing information from the user's application program (AP) or the like (step 0) is received (step 1) to determine whether or not access is prohibited due to a file abnormality. Check (step 2), if there is no prohibition, analyze this and convert it to an execution format (step 3) Access the database file and execute data reference and update processing (step 4) The presence / absence is checked (step 5), and if there is no abnormality, the journal access processing and the file saving are checked by the journal control processing (step 9), and then the data processing execution result is notified to the user AP (step 10).

When a file abnormality is detected in the database file access (step 5), a file access prohibition action is taken (step 6), a file restoration process is instructed (step 8), and then a journal control process (step 9). ). When the access monitoring is identified at the head of the input / output processing (step 2), the file recovery processing is immediately instructed without performing the database file access (step 8), and the journal control processing (step 9) is performed.

In the journal control process, it is checked whether the database file saving process is being executed (step 11), and if the saving process is not being executed, it is checked whether the saving completion notice is received from the saving process (step 12). If there is no notification, the update history information is output to the journal file (step 13), and it is checked whether the database file save processing is started from the cumulative value of the amount of data output to the journal file (step 14).
When performing the save process, the save process is activated by the notification of the process start to the file save process (step 15), and when the save process is not performed, the process is terminated as it is. If the save process is being executed (step 11), the presence or absence of a file abnormality detection in the save process is checked (step 1).
8) If the file is normal, the update history information is output to the work file and the process ends (step 19).

If a file error occurs during the save process (step 18), the access to the database file is prohibited when the file error is detected during the input / output process, so the update history information accumulated in the work file during the save process is saved. Is added to the journal file, and the process ends with the state of waiting for data file recovery. When the notification of the normal completion of the save processing is received (step 12), the update history data accumulated in the journal file before the start of the save processing is initialized (step 16), and after the save processing accumulated in the work file is started. The update history information of is output to the initialized journal file (Step 1
7), the process ends.

In the file saving process, first, one page is input from the database file in the input / output process (step 20), and the database file is checked for abnormality (step 21).
Pages are output (step 22), it is checked whether evacuation of all pages has been completed (step 23), and evacuation processing for each page is repeatedly executed until there are no remaining pages, and evacuation of all pages is performed. When it is completed (step 23), the journal control process is notified of the end of the save process (step 24), and the process ends. If the database file is abnormal (step 21), the journal control process is notified of the file abnormality (step 2).
5), the process ends.

FIG. 8 to FIG. 12 show an example of normal operation of the database file and save processing, and an operation example when a file error occurs during save processing. FIG. 8 shows a normal state after the evacuation process is completed. At this point, the database control unit outputs the update history information to the journal file while executing the input / output processing for the database file by the application program or the like. In this case, the save file is a state in which the contents of the database file are saved for each page, and the contents of the journal are accumulated update information of the database file after executing the save process. FIG. 9 and FIG. 10 show the state when the save processing is executed. As shown in FIG. 9, during the saving process, the database control unit outputs the update history information to the work file while executing the input / output process for the database file by the application program and the file saving process for each page. ing. At this point, the contents of the journal file are the same as before the start of the save process. Then, at the end of saving all pages in FIG. 10, the journal file is initialized and the update history information before the start of the save processing is discarded, and the update history information after the start of the save processing output on the work file is saved in the journal. Output to the beginning. After the evacuation process is completed, the normal state of FIG. 8 is restored.

11 and 12 show the processing when the database file becomes abnormal during execution of the save processing.
As shown in FIG. 11, since the database file is saved by the process for each page during the save process, even if the save process is interrupted due to an error in the database file at some point, the pages processed up to that point Is normally saved, and the previous saved data remains for pages that were not saved. Therefore, when the database file is interrupted due to an abnormality in the database file during the saving, the database control unit prohibits access to the database file, and after the saving process accumulated in the work file is started, as shown in FIG. The update history information is added to the update history information on the journal file before the save processing, and the recovery operation is instructed. When the database file is restored from this state, the pages saved up to the file error will be restored from the latest saved data, and the pages that could not be saved will be restored from the previous saved data.

In this way, by automatically saving the database file at regular intervals, it is possible to always prepare for the occurrence of an abnormality.

[0016]

As described above, according to the present invention, the following effects can be obtained in database system operation. (1) The database file saving process can be automated. (2) When an abnormality occurs, a new save file is always prepared, so quick recovery processing can be performed.

[Brief description of drawings]

FIG. 1 is a block diagram showing the configuration of an embodiment of the present invention.

FIG. 2 is a block diagram showing a configuration of a conventional database file saving process.

FIG. 3 is a block diagram showing the configuration of this embodiment during normal operation of the database.

FIG. 4 is a block diagram showing the configuration of the present embodiment in database file save processing.

FIG. 5 is a flowchart showing processing of input / output means.

FIG. 6 is a flowchart showing processing of journal control means.

FIG. 7 is a flowchart showing the processing of a file saving means.

[Figure 8] Illustration of the normal database operation

FIG. 9 is an explanatory diagram when executing a database save.

FIG. 10 is an explanatory diagram when executing a database save.

FIG. 11 is an explanatory diagram when a database file error occurs during the save process.

FIG. 12 is an explanatory diagram when a database file error occurs during the save process.

[Explanation of symbols]

 1 application program 2 database control unit 3 database file 4 journal file 5 work file 6 save file 7 save processing program

Claims (1)

[Claims] 1. In a database system operated on an electronic computer system, an input / output unit for performing input / output processing of a database file, a journal control unit for controlling output of a data journal file after updating the database file, A file saving means for dynamically executing a saving process without interrupting the operation of the database file is provided, and the file saving means sets an upper limit on the data amount of the data journal file after updating the database file to a fixed value. A database management method characterized in that the database system is automatically saved every time a quantity update process is executed.