JPH04255040A - Data base processor - Google Patents

Abstract

PURPOSE:To reconstitute a data base file without interrupting the execution of a user's application program and reducing the processing capacity of a relational data base system whose operation can not be aborted for a long period. CONSTITUTION:The data base system is duplicated by a main data base file 13 and a sub-data base file 14. When the reconstitution of the data base files is executed by either one of the files, the operation of the data base system is continued by the other file. Updating information following the operation is stored in a reconstitution history file 15 through a reconstitution updating history output part 11. After completing the reconstitution of the data base files, the reconstituted data base files are updated based upon the updating information stored in the file 15.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a database processing apparatus, and more particularly to a database file reorganization method in a relational database system.

0002

[Prior Art] Conventionally, in a relational database system, when the arrangement of records in a file deteriorates due to the addition or deletion of records, resulting in poor access efficiency, the system automatically processes records without changing logical definition information. The database files are being reorganized to change the location of the database.

[0003] In this reorganization method, the operation of the database system is temporarily stopped to prevent updates to the database file, the data in the database file is output to the secondary storage device, and then the data is output from the secondary storage device. A common method is to reorganize the data by sorting it and writing it back into the database file. Normally, it takes a considerable amount of time to reorganize database files, so the above method cannot be implemented in a system that cannot be stopped due to 24-hour operation.

[0004] In this case, a method may be considered in which the positions of records in the database file are changed little by little while the system is in operation to perform partial reorganization. However, even with this method, there will always be a part in the database file where updates must be stopped, so when an application program tries to access a record in that part, it may become busy and have to wait, or a deadlock may occur. This may cause problems with program execution.

Furthermore, in the above method, a large amount of extra file I/O is output to the database file during system operation. Therefore, the processing of the user's application program may be delayed, and the processing capacity of the system may be reduced.

[0006] In such conventional database systems, if the database system operation is temporarily stopped and the database files are reorganized, it is difficult to reorganize the database files in a system where operation cannot be stopped for a long time. The drawback is that it cannot be done.

[0007] Furthermore, in the case of a method in which database files are arranged little by little in parts during system operation, there are drawbacks in that execution of a user's application program is hindered and the processing capacity of the system is reduced.

[0008]

OBJECTS OF THE INVENTION The present invention has been made to eliminate the drawbacks of the conventional systems as described above. To provide a database processing device capable of reorganizing database files even in an unstoppable system.

[0009]

[Structure of the Invention] A database processing device according to the present invention includes:
first and second database files each storing files of the same data; and detachment for separating one of the first and second database files from the database system when the first and second database files are reorganized. means, database saving means for storing the contents of the database file separated from the database system by the separating means in a secondary storage device, and saving the contents of the database file based on the contents stored in the secondary storage device. a reorganization means for reorganizing; a holding means for holding update history information for the other database file when the database file is reorganized by the reorganization means; and a holding means for holding the contents of the database file reorganized by the reorganization means. The apparatus is characterized by further comprising: an updating means for updating according to the update history information held in the means.

Another database processing apparatus according to the present invention includes a creation means for creating a second database file storing a file having the same data as the first database file when reorganizing the first database file;
When reorganizing the first database file, the first
and a detaching means for detaching one of the second database files from the database system; a database save means for storing the contents of the database file detached from the database system by the detaching means in a secondary storage device; a reorganization means for reorganizing the contents of a database file based on the contents stored in a secondary storage device; and a holding means for retaining update history information for the other database file when the database file is reorganized by the reorganization means. and updating means for updating the contents of the database file reorganized by the reorganizing means in accordance with the update history information held in the holding means.

[0011]

[Embodiment] Next, an embodiment of the present invention will be described with reference to the drawings.

FIG. 1 is a block diagram showing the configuration of an embodiment of the present invention. In the figure, a host computer 1 includes a database processing device 2, an application program 3,
It is composed of an operation reception device 5. The database processing device 2 has a main database file 13.
, a secondary database file 14 , a reorganization history file 15 , a secondary storage device 16 , and a history file 19 are connected, respectively, and a console input/output device 4 is connected to the operation reception device 5 .

The database processing device 2 is composed of a database processing mechanism 6 and a database file reorganization mechanism 7. The database file reorganization mechanism 7 includes a reorganization management section 8, a database file save section 9,
It is composed of a database file reorganization section 10, an update history output section 11 during reorganization, a post-reorganization file update section 12, a subfile creation section 17, and a subfile update section 18.

FIG. 2 is a diagram showing the structure of the reorganization history file 15 of FIG. 1. In the figure, each record 15-1 to 15-n of the reorganization history file 15 is composed of a record identifier 15a, an update type 15b, and a data section 15c. The operation of one embodiment of the present invention will be explained using FIGS. 1 and 2. FIG.

First, a duplex system will be explained below. When the application program 3 issues an update request to the database file during normal operation, the database processing mechanism 6 of the database processing device 2 updates the data in the main database file 13. At this time, the database processing mechanism 6 also updates data in the sub database file 14.

When an operator issues a reorganization request to the operation receiving device 5 via the console input/output device 4, the operation receiving device 5 notifies the database processing device 2 of the reorganization request. When the database processing device 2 receives a reorganization request, the reorganization management section 8 of the database file reorganization mechanism 7 accepts the request.

When the reorganization management unit 8 receives the request,
It makes the database processing mechanism 6 stop updating the secondary database file 14, and outputs a request to output history information during reorganization. The database processing mechanism 6 inputs a unique key or a unique record identifier 15a within the file implicitly added by the database processing mechanism 6 to the update history output unit 11 during reorganization of the database file reorganization mechanism 7, and information such as additions, deletions, etc. Update type 15
A record 15 in which b and the update data section 15c are paired
Start outputting -1 to 15-n. The reorganization update history output unit 11 outputs these records 15-1 to 15-n to the reorganization history file 15. Therefore, the update history of the main database file 13 when the sub database file 14 is reorganized is recorded in the reorganization history file 15.

When a response to stop updating the secondary database file 14 is received from the database processing mechanism 6 to the reorganization management unit 8, the reorganization management unit 8 requests the database file saving unit 9 to save the data of the secondary database file 14. Output. Database file save section 9
reads data from the secondary database file 14 in accordance with a request from the reorganization management section 8 and outputs the data to the secondary storage device 16.

When the data of the secondary database file 14 has been saved to the secondary storage device 16, the reorganization management unit 8 sends a request for reorganization of the secondary database file 14 using the data saved to the secondary storage device 16 for database reorganization. output to section 10. The database reorganization unit 10 reads data from the secondary storage device 16 in accordance with a request from the reorganization management unit 8, arranges the data to improve access efficiency, and then writes it to the secondary database file 14 or indexes the data. Perform reorganization processing such as re-creation.

When the database reorganization unit 10 completes the reorganization of the secondary database file 14, the reorganization management unit 8 outputs a request to the post-reorganization file update unit 12 to reflect the updated image after the start of reorganization. The post-reorganization file update unit 12 updates record 15-1 from the reorganization history file 15 in accordance with a request from the reorganization management unit 8.
~15-n sequentially, records 15-1 to 15-n
Data section 15 in records 15-1 to 15-n according to record identifier 15a and update type 15b therein.
The reorganized secondary database file 14 is updated by c.

When the update of the secondary database file 14 catches up with the update of the main database file 13, the post-reorganization file update section 12 notifies the reorganization management section 8 of this fact. When the reorganization management section 8 receives the notification from the post-reorganization file update section 12, it issues a request for switching the updated database file to the database processing mechanism 6. In response to a request from the reorganization management unit 8, the database processing mechanism 6 switches the database file to be updated thereafter from the main database file 13 to the sub database file 14. At this time, the reorganization history file 15
Data output to continues.

When the database processing mechanism 6 notifies the reorganization management unit 8 of the completion of switching the updated database file, the reorganization management unit 8 updates the database file reorganization unit 1.
A reorganization request for the main database file 13 is output to 0. In accordance with a request from the reorganization management unit 8, the database file reorganization unit 10 arranges the data read from the secondary storage device 16 and writes it to the main database file 13 in the same manner as the reorganization processing described above. , perform reorganization processing such as rebuilding indexes.

When the database reorganization unit 10 completes the reorganization of the main database file 13, the reorganization management unit 8 outputs a request to the post-reorganization file update unit 12 to reflect the updated image after the start of reorganization. The post-reorganization file update unit 12 updates record 15-1 from the reorganization history file 15 in accordance with a request from the reorganization management unit 8.
~15-n sequentially, records 15-1 to 15-n
Data section 15 in records 15-1 to 15-n according to record identifier 15a and update type 15b therein.
The reorganized main database file 13 is updated by c.

When the update of the main database file 13 catches up with the update of the sub database file 14, the main database file 13 and the sub database file 1
The contents of 4 are exactly the same. At this point, the post-reorganization file update unit 12 notifies the reorganization management unit 8 of this fact. The reorganization management unit 8 is a post-reorganization file update unit 12
Upon receiving the notification from , it issues a request for switching the updated database file to the database processing mechanism 6 . In accordance with a request from the reorganization management unit 8, the database processing mechanism 6 transfers the database files to be updated thereafter from the secondary database file 14 to the main database file 13.
Switch to. This allows the main database file 1
The dynamic reorganization processing of 3 and the secondary database file 14 ends.

Thereafter, the secondary database file 14 is updated simultaneously with the main database file 13 by the auxiliary database processing mechanism 6 as before the reorganization.

Next, a non-duplex system will be explained below. When the application program 3 issues an update request to the database file during normal operation, the database processing mechanism 6 of the database processing device 2 updates the data in the main database file 13. At the same time, the database processing mechanism 6 outputs update records one by one to the history file 19.

When an operator issues a reorganization request to the operation receiving device 5 via the console input/output device 4, the operation receiving device 5 notifies the database processing device 2 of the reorganization request. When the database processing device 2 receives a reorganization request, the reorganization management section 8 of the database file reorganization mechanism 7 accepts the request.

[0028] When the reorganization management unit 8 receives the request,
A sub database file creation request is output to the sub file creation unit 17. The secondary file creation unit 17 reads the previously saved data from the secondary storage device 16 in accordance with a request from the reorganization management unit 8, and creates the secondary database file 14. Furthermore, when the sub-file creation unit 17 finishes creating the sub-database file 14, the reorganization management unit 8 outputs a request to update the sub-database file 14 to the sub-file update unit 18. The secondary file update unit 18 reads the update record from the history file 19 in accordance with a request from the reorganization management unit 8, and stores the updated image that has been updated since the last time the data was saved in the secondary storage device 16 into the secondary database file 14. By outputting, the secondary database 14 is made into the same image as the main database file 13, thereby temporarily duplicating the database file.

Next, the reorganization management unit 8 causes the database processing mechanism 6 to stop updating the secondary database file 14. At this time, if the secondary file updating unit 18 is updating the secondary database file 14, the reorganization management unit 8 outputs a stop request to the secondary file updating unit 18. In accordance with a request from the reorganization management unit 8, the sub file update unit 18 updates the sub database file 14 of updates made to the main database file 13 after the start of reorganization.
reflection will be stopped.

At the same time, the reorganization management section 8 outputs a request to the database processing mechanism 6 to output history information during reorganization. The database processing mechanism 6 inputs a unique key or a unique record identifier 15a within the file implicitly added by the database processing mechanism 6 to the update history output unit 11 during reorganization of the database file reorganization mechanism 7, and information such as additions, deletions, etc. Update type 15b and update data section 1
The output of records 15-1 to 15-n paired with 5c is started. The reorganization update history output unit 11 outputs these records 15-1 to 15-n to the reorganization history file 15.

When a response to stop updating the secondary database file 14 is received from the database processing mechanism 6 to the reorganization management unit 8, or from the secondary file update unit 18 to the reorganization management unit 8, the history file 19 up to the start of reorganization is sent. When the response to the effect that the update of the secondary database file 14 has been stopped after the data has been reflected in the secondary database file 14 is received, the reorganization management unit 8 sends a request to the database file save unit 9 to save the data in the secondary database file 14. Output. The database file save unit 9 saves the secondary database file 14 according to a request from the reorganization management unit 8.
, and outputs the data to the secondary storage device 16.

When the data of the secondary database file 14 has been saved to the secondary storage device 16, the reorganization management unit 8 requests database reorganization of the secondary database file 14 using the data saved to the secondary storage device 16. output to section 10. The database reorganization unit 10 reads data from the secondary storage device 16 in accordance with a request from the reorganization management unit 8, arranges the data to improve access efficiency, and then writes it to the secondary database file 14 or indexes the data. Perform reorganization processing such as re-creation.

When the database reorganization unit 10 completes the reorganization of the secondary database file 14, the reorganization management unit 8 outputs a request to the post-reorganization file update unit 12 to reflect the updated image after the start of reorganization. The post-reorganization file update unit 12 updates record 15-1 from the reorganization history file 15 in accordance with a request from the reorganization management unit 8.
~15-n sequentially, records 15-1 to 15-n
Data section 15 in records 15-1 to 15-n according to record identifier 15a and update type 15b therein.
The reorganized secondary database file 14 is updated by c.

When the update of the secondary database file 14 catches up with the update of the main database file 13, the post-reorganization file update section 12 notifies the reorganization management section 8 of this fact. When the reorganization management section 8 receives the notification from the post-reorganization file update section 12, it issues a request for switching the updated database file to the database processing mechanism 6. In response to a request from the reorganization management unit 8, the database processing mechanism 6 switches the database file to be updated thereafter from the main database file 13 to the sub database file 14. At this time, the reorganization history file 15
Data output to continues.

When the database processing mechanism 6 notifies the reorganization management unit 8 of the completion of switching the updated database file, the reorganization management unit 8 updates the database file reorganization unit 1.
A reorganization request for the main database file 13 is output to 0. In accordance with a request from the reorganization management unit 8, the database file reorganization unit 10 arranges the data read from the secondary storage device 16 and writes it to the main database file 13 in the same manner as the reorganization processing described above. , perform reorganization processing such as rebuilding indexes.

When the database reorganization unit 10 completes the reorganization of the main database file 13, the reorganization management unit 8 outputs a request to the post-reorganization file update unit 12 to reflect the updated image after the start of reorganization. The post-reorganization file update unit 12 updates record 15-1 from the reorganization history file 15 in accordance with a request from the reorganization management unit 8.
~15-n sequentially, records 15-1 to 15-n
Data section 15 in records 15-1 to 15-n according to record identifier 15a and update type 15b therein.
The reorganized main database file 13 is updated by c.

When the update of the main database file 13 catches up with the update of the sub database file 14, the main database file 13 and the sub database file 1
The contents of 4 are exactly the same. At this point, the post-reorganization file update unit 12 notifies the reorganization management unit 8 of this fact. The reorganization management unit 8 is a post-reorganization file update unit 12
Upon receiving the notification from , it issues a request for switching the updated database file to the database processing mechanism 6 . In accordance with a request from the reorganization management unit 8, the database processing mechanism 6 transfers the database files to be updated thereafter from the secondary database file 14 to the main database file 13.
Switch to. This allows the main database file 1
The dynamic reorganization processing of 3 and the secondary database file 14 ends.

Thereafter, the data of the secondary database file 14 is outputted to the secondary storage device 16 by the database file save section 9 for the next reorganization process, and then released.

Note that after the sub database 14 is created by the sub file creation section 17, the sub file update section 18
It is also possible to reorganize the main database file 13 first by switching the database file using the database processing mechanism 6 when the main database file 13 is made into the same image as the main database file 13.

[0040] In this way, the database system is divided into the main database file 13 and the sub database file 14.
When the database file is reorganized using one of them, the database system continues to operate using the other one, and the update history output unit 11 outputs the updated information at that time. It is stored in the reorganization history file 15 via the reorganization history file 15 after the database file reorganization is completed.
By updating the reorganized database file based on the update information, the database file reorganization process can be performed without stopping the database system in operation.

[0041]Also, even though the database file is reorganized during operation of the database system, no I/O is performed on the database file being accessed by the user, so the application program 3 On the other hand, file access is never busy or deadlock occurs. Therefore, the user's application program is not adversely affected and the processing speed is not reduced. In other words, without interfering with the execution of user application programs or reducing system processing capacity,
Database files can be reorganized even in systems where operation cannot be stopped for a long time.

[0042]

As explained above, according to the present invention, when the database files of a database system are duplicated and one of them is used to reorganize the database file, the other one is used to reorganize the database file. By continuing the operation, retaining the updated information at that time, and updating the reorganized database file based on the updated information after the database file reorganization is completed, the user application This has the effect that database files can be reorganized even in systems that cannot be stopped for long periods of time without interfering with program execution or reducing system processing capacity.

[Brief explanation of the drawing]

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

FIG. 2 is a diagram showing the structure of the reorganization history file in FIG. 1;

[Explanation of symbols]

1 Host computer 2 Database processing device 6 Database processing mechanism 7 Database file reorganization mechanism 8 Reorganization management section 9 Database file save section 10 Database file reorganization section 11 Update history output section during reorganization 12 Post-reorganization file update section 13 Main Database file 14 Sub-database file 15 Reorganization history file 16 Secondary storage device 17 Sub-file creation section 18 Sub-file update section 19 History file

Claims (2)

[Claims] 1. First and second database files that store files of the same data, respectively; and when the first and second database files are reorganized, the first
and a detaching means for detaching one of the second database files from the database system; a database saving means for storing the contents of the database file detached from the database system by the detaching means in a secondary storage device; a reorganization means for reorganizing the contents of the database file based on the contents stored in the second storage device; a holding means for retaining update history information for the other database file when the database file is reorganized by the reorganization means; A database processing apparatus comprising: an updating means for updating the contents of the database file reorganized by the reorganizing means in accordance with the update history information held in the holding means. 2. Creation means for creating a second database file storing a file with the same data as the first database file when reorganizing the first database file; and when reorganizing the first database file. a detaching means for detaching one of the first and second database files from the database system; and a database saving means for storing the contents of the database file detached from the database system by the detaching means in a secondary storage device. and a reorganization means for reorganizing the contents of the database file based on the contents stored in the secondary storage device, and retaining update history information for the other database file when the database file is reorganized by the reorganization means. A database processing device comprising: a holding means; and an updating means for updating the contents of the database file reorganized by the reorganizing means in accordance with the update history information held in the holding means.