JPH0877050A - Device and method for reconstituting data base - Google Patents

Abstract

PURPOSE: To reconstitute a data base which does not have a stand-by system into an on-line data base by reconstituting the data base, which were reconstituted by an in-use system and a stand-by system, by expansion into an old table and a new table in one memory. CONSTITUTION: The data base reconstituting device is so constituted that the old table 203 in the memory 102 contains information on the data base to be reconstituted and the new table 206 contains information after reconstitution. When information in the old table 203 is updated as a result of access from an application program 202, an update history recording means 204 stores an updated history and a matching means 210 after storing all the information of the old table 203 in the new table 206 reflects the information of the updated old table 203 on the new table 206 on the basis of the history stored in the update history recording means 204.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a database restructuring apparatus and a database restructuring method, and more particularly, to a database management system (DBMS) which is used for an online system by changing a schema while continuing service. The present invention relates to a database reconstructing device and a database reconstructing method for reconstructing an existing database.

[0002]

2. Description of the Related Art Restructuring of a database targets the physical structure of the database in order to improve data storage efficiency and processing efficiency based on the operational status of the database.
The storage area is expanded, reduced, and the storage device is changed (from the active system to the standby system).

Reconstruction of a conventional database has a method of changing a schema that describes a logical structure and a physical structure of the database. The database schema includes a conceptual schema that models real-world data, an external schema that describes data from the user's perspective, and an internal schema that describes the physical structure.By changing these schemas, the database Reconstruction is performed.

Further, the reorganization accompanied by the movement of the data entity in the database file is realized in the system in which the active system and the standby system are duplicated. In such a duplicated database system, while the database system continues to operate in the active system,
The DB of the active system is copied to the standby system, reconfiguration is performed on the standby system, and the contents of the update made on the active system during the reconfiguration work are finally reflected on the standby system and switched.

[0005]

However, the above-mentioned conventional system requires a spare database to reconstruct the database, and a system without a spare system requires
There is a problem that it cannot be realized because the data cannot be matched except for stopping the operation of the active system.

The present invention has been made in view of the above points, and provides a database reconstructing apparatus and a database reconstructing method capable of reconstructing an online database in a single database system having no backup system. The purpose is to provide.

[0007]

FIG. 1 is a block diagram showing the principle of the present invention.

According to the present invention, in a database reconfiguring device for reconfiguring a database in a database management system, an old table 203 for storing information on a database to be reconfigured, a new table 206 for storing information after reconfiguration, Update history storage unit 2 that accumulates updated history when information in the old table 203 is updated by access from the application program 202
After storing all the information of the old table 203 in the new table 206, the information of the old table 203 updated based on the history accumulated in the update history recording unit 204 is stored in the new table. And a matching means 210 for reflecting the same in 206.

Further, the present invention has the access switching means 211 for switching the access target of the application program 202 from the old table 203 to the new table 206 after the matching means 210 completes the information matching processing.

FIG. 2 is a flow chart for explaining the principle of the present invention.

According to the present invention, in a database restructuring method for reconfiguring a database in a database management system, an old table to be accessed by an application program and a new table for storing reconfigured information are stored in one memory. It is generated (step 1), the information in the database is expanded into the old table (step 2), and the information in the old table is reconfigured into the new table.

In the reconfiguration, the information of the old table to be accessed is copied to the new table while the application program is running (step 3), and the information of the old table updated by the application program during copying is identified ( At step 4), when the copying is completed (step 5), the updated old table information is reflected on the new table information (step 6).

In step 3 above, the identifier of the record of the old table updated during copying is identified,
Remember.

After step 4, that is, after the updated old table information is reflected in the new table information, the access target is switched from the old table to the new table information (step 7).

Further, according to the present invention, when the information of the old table is being reflected in the information of the new table or when the information of the old table is updated after the reflection, the updated information is reflected again in the new table.

[0016]

According to the present invention, the restructuring of the database, which has been conventionally performed in the active system and the standby system, is expanded into the old table and the new table in one memory to perform the reconfiguration.

The present invention creates a table (new table) for storing reconstructed records of a table to be reconstructed (in the above, the old table), and continues the access processing of the application program to the old table. ,
All the information of the old table is stored in the new table while recording the identifier of the record of the old table updated by the application program as the update history record.
Therefore, after the information in the old table is copied to the new table, the updated information of the old table corresponding to the identifier of the update history record is reflected in the new table by referring to the update history record, so that the information can be consistent. Is possible.

Further, even when the information of the old table is updated until the application program is stopped or during the matching process, the information of the old table at the final point is updated to the new table by referring to the update history record again. Since it can be reflected in, it is possible to achieve consistent consistency.

Further, after the information matching process is completed, the access target of the application program is switched from the old table to the new table. This makes it possible to access the table in a consistent state.

[0020]

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

The present invention is implemented in the environment shown in FIG.
That is, the database 103 is expanded on the main memory 102, and the processor 101 executes an application program to perform processing. At this time, the database 103 is managed by a database management system (DBMS).

FIG. 4 shows the structure of a system for reconstructing a database according to an embodiment of the present invention. The system shown in the figure operates on the system as shown in FIG. The processor 101 includes an access unit 201, a data content conversion unit 207, an application program 20.
2, 205. The main memory 102 has an old table 203, a new table 206, and an update history recording unit 204, and the contents of the database 103 are expanded in the old table 203. Therefore, the old table 203 is a table before reconstruction and is accessed by the application program 202. The new table 206 is a table generated by reconfiguration,
The copy information and update information of the old table 203 are stored.

The access unit 201 has a table 203 older than the application programs 202 and 205, or
While controlling access to the new table 206, processing such as writing and referring to the update history information of the old table in the update history recording unit 204 is performed. The data content conversion unit 207
When it is necessary to convert the contents of the data during the reconstruction, the contents of the data are updated according to the data contents conversion application program defined by the user. In addition, the new table 206 may be reconfigured if necessary.
New application program 205 that targets
Replace with.

In the update history recording unit 204, the contents of the old table 203 being reconstructed are
When updated by 02, the record ID of the old table 203 is recorded as the update history.

FIG. 5 is a flow chart for explaining the processing operation of one embodiment of the present invention.

Step 101) First, when reconstructing the database, the contents of the database 103 are expanded into the old table 203 in the main memory 102, and the application program 202 accesses the old table 203 via the access unit 201. .

(Step 102) The application program 202 creates a new table 206 in the main memory 102 for storing the reconstructed record.

Step 103) All old tables 203
If the record is already copied, the process proceeds to step 109.

Step 104) The application program 202 causes the access table 201 to access the old table 20.
Read the record in 3.

Step 105) The data format conversion processing is performed by the data format conversion application program on the record read from the old table 203. At this time, if the application program 202 specifies to perform the data content conversion process, the data content conversion is further performed using the application program of the data content conversion unit 207.

Here, the data format conversion is to convert the data storage format so as to match the field format of the new table 206. For example, conversion is performed to expand an 8-bit integer field to 16 bits, or to expand a character field from 32 characters to 48 characters.

Further, the content conversion is a conversion in which the content and meaning of a numerical field are uniformly changed. For example, in the "price" field, a price excluding consumption tax has been entered until now. However, it is a conversion that changes to a price including tax as the application program changes.

Further, the format conversion and the content conversion may be performed at the same time, and these can be arbitrarily converted by an application program.

Step 106) The record of the old table 203 which has been subjected to the data format conversion processing and the data content conversion processing in the above step 105 is the new table 2
It is stored in 06.

(Step 107) If the record of the old table 203 is updated by the application program 202, the process proceeds to Step 108,
If it has not been updated, the process proceeds to step 103.

Step 108) The access unit 201, when the record of the old table 203 is updated,
The ID of the updated record is stored in the update history recording unit 204.

Step 109) When the copying of all the records of the old table is completed, the application program processing is stopped.

Step 110) The access unit 201 determines the ID of the record that needs to be reconverted by the update history recording unit 204.
Take out. The record ID fetched here is a record of the old table 203 that has been updated n (n ≧ 1) times by the application program 202.

Step 111) I of the retrieved record
The record corresponding to D is read from the old table 203.

Step 112) Data conversion is performed so that the record taken out from the old table 203 is adapted to the new table 206.

Step 113) The data-converted record of the old table 203 is stored in the new table 206.

(Step 114) Here, if all the processing of the ID recorded in the update history recording unit 204 has been completed, the process proceeds to Step 115, and if there are still unprocessed IDs, Go to step 110.

Step 115) The table accessed by the application program 202 is the old table 203.
To the new table 206.

(Step 116) The prohibition of starting the application program 202 stopped in Step 109 is released. Also, if necessary, the application program to be used is switched to another program 205.

Next, each state of the old table 203 and the new table will be described.

FIG. 6 shows a normal operation state in which one embodiment of the present invention is not reconfigured. The application program 202 allows the application program 20
2 is the record numbers “2” and “8” of the old table 203
Is being accessed, and the record numbers “4” and “6” are referenced.

FIG. 7 shows a state in which the information of the old table is copied to the new table according to the embodiment of the present invention. In order to reconfigure the database by starting the application program 202, the record numbers 1 to 1 in the old table 203
4 is subjected to data format conversion processing and data content conversion processing and is copied to record numbers 1 to 4 of the new table. Further, the record numbers “1” and “3” of the old table 203 are updated. Therefore, the update history recording unit 204 stores the code I of the old table 203 as an update history list.
D "1" and "3" are recorded.

FIG. 8 shows a state in which the old table according to the embodiment of the present invention is updated again. In the figure, all the records (10 records in the figure) of the old table are the new table 20.
6 is recorded in the list of the update history recording unit 204, and “5, 2, 8, 1, 3” is recorded as the record ID of the updated old table. In this case, all the records (updated records) of the old table 203 with the ID recorded in the update history list of the update history recording unit 204 are read, data conversion is performed, and the new table 206 is stored.

Next, a specific example will be described. Figure 9
Shows respective states of the old table, new table, and update history recording unit according to the embodiment of the present invention.

It is assumed that the application program 202 is activated and the database restructuring process is started.

Here, first, the data “A” of the record number “1” of the old table 203 is copied to the new table 206. At this time, the old table 203 is not updated.

Next, the data "B" of the record number "2" of the old table 203 is copied to the new table 206. At this time, the data of the old table record number “1” is updated from “A” to “α”. Therefore, the record number “1” of the old table 203 is recorded in the list of the update history recording unit 204.

Further, the data “C” of the record number “3” of the old table 203 is copied to the new table 206.

Record number "4" of old table 203
Data “D” of the above is copied to the new table 206.

The data "I" of the record number "9" of the old table 203 is copied to the new table 206. At this time, the data “G” of the record number “7” of the old table 203 is updated to “θ”. Therefore, "1, 2, 4, 7" is recorded in the list of the update history recording unit 204 at this time.

The data "J" of the last record number "10" of the old table 203 is copied to the new table 206. The contents of the last record number "10" are set in the new table 2
"1, 2, 4, 7" is recorded in the list of the update history recording unit 204 at the time of copying to 06.

Since all the data in the old table 203 has been copied, the record I of the updated old table 203 recorded in the update history recording unit 204 is recorded.
The contents of the new table 206 are updated based on D.
The updated result is as follows.

[0058]

[Table 1]

Here, it is assumed that the contents of the old table 203 are further updated by the application program 202 during the reflection process. In this example, it is assumed that the data of the record number “6” in the old table 203 is updated from “F” to “γ”, and the data of the record number “3” is updated from “C” to “ε”. At this time, the list of the update history recording unit 204 is “1, 2, 4, 7, 6, 3”, and the updated data has the record number “6” corresponding to the record ID of the old table 203. The updated data is reflected in "" and "3". That is, the data “F” is updated to “γ” and “C” is updated to “ε”. Therefore, the final reflection data of the new table is as follows.

[0060]

[Table 2]

As can be seen from the above example, the update history is recorded in the update history recording unit 204, and when the data conversion and the storage of the new table are completed, the ID of the record updated by the update history recording unit 204 ( Number) is extracted, the record is converted again, and stored in the new table 206.

Similarly, when the information in the old table 203 is being updated while the updated information is being reflected in the new table 206 (or from the end of the reflecting process to the completion of the application program start prohibition), the update history is similarly changed. Recording unit 2
The data can be matched by referring to the list No. 04 and performing the reflection process on the new table 206 again.

In the above embodiment, the old table 20 is used.
After the copying process of the record of No. 3 to the new table 206 is completed, while executing the matching process, the execution of the application program is stopped, the matching process is performed based on the list of the update history recording unit 204, and the re-execution is performed. actually,
Since the number of matched records is one or two, the time period for which the application program is stopped is practically short and can be regarded as uninterrupted.

The present invention is not limited to the above embodiments, but various modifications and applications are possible within the scope of the claims.

[0065]

As described above, according to the present invention, in a non-redundant database system, the database access process is not interrupted and the database schema is changed / the data contents are collectively updated without changing the system operating state. The configuration can be performed, the service interruption time due to database maintenance can be extremely shortened, and the operation rate of the database can be improved.

[Brief description of drawings]

FIG. 1 is a principle configuration diagram of the present invention.

FIG. 2 is a flow chart for explaining the principle of the present invention.

FIG. 3 is a system configuration diagram of an embodiment of the present invention.

FIG. 4 is a configuration diagram of a database management system according to an embodiment of the present invention.

FIG. 5 is a flowchart illustrating a processing operation according to an embodiment of the present invention.

FIG. 6 is a diagram showing a normal operation state in which reconstruction is not performed according to an embodiment of the present invention.

FIG. 7 is a diagram showing a state in which information on an old table is copied to a new table according to an embodiment of the present invention.

FIG. 8 is a diagram showing a state in which an old table according to an embodiment of the present invention is updated again.

FIG. 9 is a diagram showing respective states of an old table, a new table, and an update history recording unit according to an embodiment of the present invention.

[Explanation of symbols]

 101 processor 102 main memory 103 database 200 database management system (DBMS) 201 access unit 202 application program 203 old table 204 update history recording unit 205 new application program 206 new table 207 data content conversion unit 210 matching unit 211 access switching unit

Claims (7)

[Claims] 1. A database reconfiguring apparatus for reconfiguring a database while continuing the operation of an application program in a database management system, wherein an old table storing information of the database to be reconfigured and information after reconfiguration are displayed. One memory having a new table to be stored and update history storage means for accumulating an updated history when information of the old table is updated by access from an application program, and all information of the old table Is stored in the new table, and a matching means for storing the updated information of the old table in the new table based on the history accumulated in the update history storage means. Configuration device. 2. The database reconfiguring apparatus according to claim 1, further comprising an access switching unit that switches an access target from the old table to the new table after the matching unit completes the information matching process. 3. A database restructuring method for reconfiguring a database while continuing the operation of an application program in a database management system, wherein an old table to be accessed by the application program is reconfigured in one memory. A new table for storing information is generated, the information of the database is expanded to the old table, and the information of the old table is reconfigured to the new table. 4. The information of the old table to be accessed is copied to the new table while the application program is running, and the information of the old table updated by the application program is identified during copying, and copying is performed. The database restructuring method according to claim 3, wherein the updated information of the old table is reflected in the information of the new table when the processing is completed. 5. The database restructuring method according to claim 3, wherein the identifier of the record of the old table updated during copying is identified and stored. 6. The database restructuring method according to claim 4, wherein after the updated information of the old table is reflected in the information of the new table, the access target is switched to the new table. 7. The updated information is reflected again in the new table when the information in the old table is updated during or after the information in the old table is reflected in the information in the new table. Item 4. The database reconstruction method according to item 4.