JPH09160817A - Database converting system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a database converting system whereby a database requiring the conversion of data form is automatically detected and the form conversion of data added in the detected database is dynamically executed without stopping normal processing such as an on-line processing, etc. SOLUTION: This system is provided with a database access part 22 detecting access to the database 32 by the new data form and a database converting part 24 converting data added in the old before-conversion database 30 into data by the different data form so that the database 32 is automatically and newly generated without stopping the system when an access request as against the database 32 is detected for the first time and access is performed for the database 32 by the new data form after conversion at the point of time when generation is executed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a database conversion method in a database management system built on an information processing system, and in particular, converts data stored in a database and saves it in another database without stopping the system. Database conversion method.

[0002]

2. Description of the Related Art The field length of a database built on an information processing system is changed in accordance with the change of the usage pattern, or it is changed when the model is changed to a model having a different handling of data such as a code system. When it became necessary to change to the data format, it was a usual technique to stop the system and execute a database migration program to create a new database.

In such a method, the system may be forced to stop for a long time. Therefore, as a solution to this problem, Japanese Patent Laid-Open No. 233408/1993 discloses "a migration method in an online processing system." There is. 12 to 15 are block diagrams showing this conventional "migration method in an online processing system",
The database is migrated through the illustrated four phases during the online processing.

According to this method, in a system having a dual disk configuration, the online work is continued in one system, the migration work is carried out in another system, and the online service is restarted from the new system when the migration work is completed. By doing so, it is possible to minimize the downtime of the service due to the migration.

Further, as a method taken for dynamically performing the conversion processing of these databases without stopping the system, Japanese Patent Publication No. 4-77340 (JP-A-60-34040).
No. 10362), there is a “dynamic change method of data item in record type data”. FIG.
16 is a block diagram showing a “dynamic change method of data items in record-type data”. FIG.
0, relation operation system 11, record access system 12, logical database access system 13, physical database access system 1
4, an external schema 15, an internal schema 16 and a database 17 are shown.

Records in a file such as a database have a fixed record length, and once created, the records that make up the file cannot be changed. This method improves on this because it only added data items. That is, for each data item, an item cell holding the attribute of the data item in advance, a physical array order pointer provided between the item cells for indicating the physical array order on the record of the data item, Information such as a display order pointer indicating a logical display order is provided in the record definition storage unit, and by using the information in these record definition storage units, data item addition, deletion, data item attribute change, etc. Even when the record definition of is changed, the record definition change is dealt with without changing the record existing in the file created before this.

[0007]

However, according to the migration method in the conventional online processing system disclosed in Japanese Patent Laid-Open No. 233408/1993, the online service is serialized by a single system in a system having a dual disk configuration. As it is to carry out the migration work on another system as it is, it is a big premise that the system's disk is a duplicated structure, and in the system that does not use the disk duplication structure, the disk capacity is Even if there was a margin, there was a problem that this method could not be adopted. In addition, in such a method, a migration database and a conversion database are intentionally prepared, and the database used by the application is selected from among the many existing databases, and the migration database is migrated. The operation of the operator to carry out the work of was essential.

Further, in the conventional method of dynamically changing data items disclosed in Japanese Patent Laid-Open No. 60-10362, in order to protect previously created data items as they are, the physical arrangement of records and logical The physical arrangement must be stored in advance as a record definition storage unit, and it is not intended to make a dynamic change during the use of the system.
In addition, if the number of records changed by this method increases, the processing overhead will increase in the end, so to improve performance, it is necessary to convert all records to the latest format all at once. .

Further, in recent years, not only changes in the record array due to simple addition and deletion of data items, changes in data items due to changes in attributes of data items, but also due to migration of databases between different models, for example. There is also a desire to completely change the format of data items,
The need to change large numbers of data items is increasing. For example, in the case of migrating a database between different models, it is possible to change from one character code to another character code. In such a case, there is a change in the data format that changes the field length, so it is difficult to handle with the conventional method, and eventually, there is no choice but to take a method of batch conversion of the data format. There was a problem of becoming.

The present invention has been made to solve the above problems, and an object thereof is to automatically detect a database that requires conversion of a data format, and to detect the data included in the detected database. It is an object of the present invention to provide a database conversion method capable of dynamically performing format conversion without stopping normal processing such as online processing.

[0011]

In order to achieve the above object, the database conversion method in the present invention is
A first database that stores data in the first data format, a data format detection unit that detects access in the second data format, and a second data that differs from the first data format in the first database. Data format conversion means for performing a data format conversion process of converting to a data format of, and a second database for storing the converted data in the second data format, wherein the second database is It is characterized in that it is automatically generated when the access in the second data format is detected for the first time.

The data format converting means is characterized in that the entire first database is converted when an access in the second data format is detected for the first time.

Further, the data format conversion means is characterized in that conversion is carried out in units of tables.

Further, the data format conversion means is characterized in that conversion is performed in record units.

As described above, since the second database is automatically generated when the access in the second data format is detected for the first time, the system administrator, etc.
The data format conversion process can be automatically detected without specifying the database, and the second database that needs the conversion process can be automatically detected without stopping the system and performing other online processes in parallel. It can be automatically generated while running.

Further, the present invention is characterized in that the second database is hidden during the data format conversion processing. As a result, the existence of the database being converted can be hidden, and thus user access to the database can be prevented.

The present invention is characterized by further comprising storage area size determining means for determining the size of the storage area of the data stored in the second database.

The storage area size determining means is characterized by having a size of a data storage area automatically calculated and obtained.

Further, the storage area size determining means is characterized by having a setting value from the outside as a size of the data storage area.

Thus, the field length for storing the data converted when the second database is created can be expanded / reduced.

Further, the present invention is characterized in that the response of the processing other than the data format conversion processing is maintained.

Therefore, when the data format conversion means has a multiprocessor configuration, the data format conversion processing is performed only by a specific processor.

Further, the priority for executing the data format conversion processing is set low.

Further, the present invention is a database conversion system characterized by ensuring data consistency during data format conversion processing.

Therefore, the access recording means for recording the history of update access to the first database during the data format conversion processing in the log file, and the means for reflecting the content recorded in the log file in the second database And having.

Further, it is characterized in that update access processing to the database during the data format conversion processing is prohibited.
After the data format conversion process is completed, the update access process is restarted.

[0027]

BEST MODE FOR CARRYING OUT THE INVENTION Preferred embodiments of the present invention will be described below with reference to the drawings.

Embodiment 1. FIG. 1 is a schematic configuration diagram of an information processing system having a database conversion method according to the present invention. The system mainly includes a database management system 20 having a database access unit 22 and a database conversion unit 24, and manages the databases 30 and 32 according to an input setting from an application program 26 or a system administrator 28. In the present system, when it is necessary to change the first database 30 that stores data in the first data format to a different data format, the second database 32 is newly created and the first data format is changed. The data in the second data format obtained by conversion is stored. Of these, the database access unit 22
Is a data format detecting means for detecting access by the second data format. The database conversion unit 24 is a data format conversion unit that performs a data format conversion process of converting data in the first database 30 in the first data format into a different second data format.

As a method of accessing the database,
A user inputs a command or executes an application program. The application program 26 in the present embodiment generically refers to these methods.
In the following description, each database 30 will be defined in the database language included in the application program
32 will be described as accessing. The system administrator 28 also has an operation by the administrator and an access method by a database management program, but the system administrator 28 inputs the method.

The information processing system in this embodiment is constructed by a general computer system.
Therefore, the database access unit 22 and the database conversion unit 24 are realized by the CPU executing the application programs that perform the above processes. Further, the application program 26 is the same or a computer connected to the database management system.
Further, a keyboard, a mouse and the like are connected as means for inputting by the user and the system administrator.

The data format in this embodiment refers to setting conditions for the database or each data such as field length and code system. There is no compatibility between databases with different data formats even if they have the same data. For example, an application program that can access the database 32 after conversion by the second data format cannot normally access the database 30 before conversion by the data format. Conversely, the application program that can access the database 30 before conversion is the database 3 after conversion.
No access can be normally made to 2.
Therefore, the database access unit 22 in the present embodiment detects the access requests to the database before and after conversion in this way. Further, the database conversion unit 24 converts the data included in the database 30 into a different data format and stores it in the database 32.

Generally, the data in the existing database is converted into a different data format based on the existing database, and a new database is created to store the converted data, which is characteristic of the present embodiment. This makes it possible to detect an access request to the converted database, and to automatically create a new database that stores the converted data when the access request is detected for the first time, which is the database 32 in the present embodiment. That is what I did. And the database 30 before conversion
Data format conversion processing is performed on the entire database 3
2 is to be completed. As a result, the data format conversion process can be performed without stopping the system that is performing normal processes such as online processes.

FIG. 2 shows the processing in this embodiment.
Although it is a flowchart shown in correspondence with the configuration shown in FIG. 2, the operation of the present embodiment will be described next with reference to FIGS. Initially, the database 32 has not been created yet. For the sake of explanation, the existing database 30 will be referred to as a pre-conversion database, and the newly created database 32 will be referred to as a post-conversion database.

As described above, the old-style database 30 used until now exists on this system. Here, due to the revision of the software, an incompatible database of a new data format appears, and an application program conforming to the data format comes to be used. As described above, in order to execute the application program according to the new data format database, the old data format database cannot be used unless it is converted to the new data format database.

In the present embodiment, first, the application program 26 according to the data format of this new database is executed on this system. The application program 26 accesses the converted database 32 via the database access unit 22 in the course of its execution. At this time, the database access unit 2
2 detects this database access. At this point, the post-conversion database 32 has not been created yet, so this database access is performed by the pre-conversion database 3
Assume access to 0. If the database names of the pre-conversion database 30 and the post-conversion database 32 are the same and the database to be accessed is specified using the database name, the above-mentioned assumption is easy and the pre-conversion database 30 is accessed. be able to.

However, since a database having a different data format is actually accessed, it cannot be accessed normally. Therefore, the database access unit 22
This operation causes the application program 26
Determines that the data conforms to the new data format. In this way, it is possible to detect that the access is based on the new data format (step 100). At this stage, the database access unit 22 activates the data format conversion process of the database (step 110).
As a result, the database conversion unit 24 converts the data format of the entire pre-conversion database 30 (step 12
0) Further, the converted database 32 is automatically generated, and the converted data is stored in the converted database 32 (step 130).

As described above, according to the present embodiment,
A system administrator or the like can automatically detect a database that needs to be converted, even if a database that should be subjected to the data format conversion process is not designated. That is, a database of a new format corresponding to the database actually accessed by the application program of the new data format for the first time can be automatically created only when necessary. Then, the application program in the new data format that follows is the automatically created converted database 3
2 will be accessible. Of course, the pre-conversion database 30 will not be lost unless it is deleted.
In particular, according to the present embodiment, it is possible to create a new database with a different data format during online processing, so there is no need to stop the system for this data format conversion processing. Further, not only the system is not stopped, but the data format conversion process can be dynamically performed in parallel with the online process.
Further, in this embodiment, the disk device does not have to be duplicated.

The database access unit 22 determines whether or not the access is based on the new data format based on the result of access to the existing database 30. For example, the application program 2
Various methods are conceivable, such as referring to the version of the database language included in 6 or providing an argument to determine whether the access is based on the new data format. This is a design time term only and is the scope of application of the invention.

Further, in the present embodiment, for convenience of explanation,
The pre-conversion database 30 and the post-conversion database 32 are illustrated as if they are different disk devices, but of course, if there is sufficient disk capacity, they are created as logically different databases in the same disk device. It is also possible to do so. Also, although a pair of pre-conversion and post-conversion databases has been described, a plurality of sets can be implemented.

Embodiment 2. FIG. 3 is a diagram showing a general configuration of the database. The database 40 has a plurality of tables 41 and 42 inside, and each table 4
1 and 42 have a plurality of records 43 to 45 and 4 respectively.
6 to 48 are registered. The same applies to the databases 30 and 32 in FIG.

By the way, in the first embodiment,
When the database was accessed for the first time with the new data format, the data format was converted for the entire database. The second embodiment is characterized in that the data format conversion is performed in table units.

That is, similarly to the first embodiment, when the access by the new data format is detected, the data format conversion process of the database is started, the converted database 32 is automatically generated, and the converted data is converted into the converted database 32. However, in the present embodiment, the converted database 32 is automatically generated and only the table including the data to be accessed is converted. As a result, the time required for the initial conversion process can be shortened as compared with the first embodiment in which the entire database is converted. First converted database 32
For the application program that accesses the, the data of the new data format can be accessed as in the first embodiment, and the access time is shortened as compared with the first embodiment. The description of the data format conversion process is omitted because it is the same as that of the first embodiment except that the target of the data format conversion process is not the entire database but only the table including the required data.

Once the converted database 32 is created, in the future, if the data format of the table to be accessed has not been converted, the data format conversion process will be performed on that table at the point of access. Only after that, the new data will be registered in the converted database 32. Of course, if the table to be accessed has already been converted, the converted database 32
The table registered in will be used as is. The database access unit 22 starts the data format conversion process when there is a corresponding database 32 but no corresponding table, but the above process is repeated to eventually convert the entire database. Will be seen.

As described above, according to the present embodiment,
It is possible to obtain the same effect as that of the first embodiment, and since the data format conversion process is performed for each table, it is possible to shorten the time required for the conversion process in the initial stage.

Embodiment 3. In the first embodiment, the data format conversion process is performed on the entire database, and in the second embodiment, the data format conversion process is performed on a table basis. However, as in the present embodiment, the process may be performed on a record basis. Good. The operation of this embodiment is the same as that of the second embodiment except that the unit to be converted is a record, not a table, and therefore a description thereof will be omitted. As described above, according to the present embodiment, the same effect as that of the second embodiment can be obtained, and the data format conversion process is performed for each record, so that the time required for the initial conversion process is further shortened. be able to.

Fourth Embodiment FIG. 4 is a flowchart showing the processing according to the fourth embodiment of the present invention in association with the configuration shown in FIG. The basic processing flow is
Although it is almost the same as each of the above-described embodiments, a characteristic of this embodiment is that the post-conversion database 32 concealment process is performed as the step following the step 120 of performing the database data format conversion process. This is the addition of step 121. That is, when the data format conversion process is performed, the generated converted database 32 is set so that it cannot be accessed by a normal user. When such a data format conversion process is performed, if the intermediate file, that is, the post-conversion database 32 being processed is visible to the user, there is a possibility of erroneously accessing the database and causing a failure, which can be prevented. .

The concealment process itself of the post-conversion database 32 uses a method of controlling so-called file access permission. For example, taking UNIX system call interface as an example, chmod (conversion database name, access permission); This can be achieved by using the customary interface and specifying the permissions that prohibit access to the copy database.

In this case, the file name of the database and
As the access permission, writing may be prohibited, or reading may be prohibited in order to prevent misunderstanding caused by reading the file. It can also be realized by using a method of creating a hidden file.

Embodiment 5. FIG. 5 is a flowchart showing the processing in the fifth embodiment of the present invention in association with the configuration shown in FIG. The basic processing flow is
Although it is almost the same as each of the above-described embodiments, a characteristic of this embodiment is that each step of the database is performed at the time of the conversion step as a step following the step 120 of performing the data format conversion processing of the database. A step 122 for determining whether the field is expanded or contracted is provided, and if it is determined that the field is expanded or contracted, a step 123 for automatically calculating a new size of the expanded or contracted field is performed. Is to get a new field size.

The application program 26 for accessing such a database holds attribute information of each field of the database in order to access it. By extracting the information, the size of the area for storing the converted data, that is, the length of each field of the converted database 32 can be determined. For example, if the field stores only binary data,
Fields will rarely grow or shrink even if the coding scheme changes. However, if the field stores character data, there is a high possibility that the field length may be changed by changing the code system. In this way, the possibility of changing the field length can be determined from the extracted field information of the database.

More specifically, the original database is
Only English is supported and all character codes are 1.
Suppose it was expressed in bytes. Suppose that the purpose of database migration is to support Japanese. Japanese kanji codes are usually 2 bytes and some 3 bytes, and the field that was assumed to be 80 characters in English is 8
If we wanted to be able to handle 0 characters, we would simply need a field of 160 bytes or more. Of course, depending on the conditions, if there is a field that contains only one byte of English in a particular field, it may be considered that there is no need to expand that field. On the other hand, from the request to change Japanese software to English only, or to simply reduce the disk capacity,
It may be possible to uniformly reduce a certain field.

In this embodiment, the database conversion unit 24 determines the field length of the data stored in the converted database 32. Therefore, the database conversion unit 24 extracts the attribute information of each field of the database included in the application program 26, and automatically calculates each field length in the converted database 32 based on this information (steps 122 and 123).
If there is a field to be expanded or contracted, the converted database 32 is created with a record length according to the size of each automatically calculated field (step 130).

As described above, according to this embodiment, it is possible to automatically expand / reduce the field length for storing the converted data when the converted database 32 is created.

Sixth Embodiment FIG. 6 is a flowchart showing the processing in the sixth embodiment of the present invention in association with the configuration shown in FIG. The basic processing flow is
Although it is almost the same as each of the above-described embodiments, a characteristic of this embodiment is that, after the step 120 for performing the data format conversion processing of the database, the post-conversion database after the conversion processing is performed. The field length of each field of 32 is manually input as an operation of the system administrator 28, and a step 124 for reading this input is provided. That is, in the fifth embodiment, the field length of the converted database 32 is obtained by automatic calculation, but the present embodiment is characterized in that the set value from the outside is used as the field length. .

Various data can be considered in each field of the pre-conversion database 30. For example, assume that the database is a database that manages sales of products. In this case, if there is a field indicating the price of the product, it is a field in which only numbers are stored, and in this case, it is almost unlikely that the field length is changed by code conversion.

However, even in such a case, it is conceivable that the database tries to expand the amount field in order to withstand the increase in the transaction amount of the commodity. In the case of a field in which characters are used like a product name field, the field length can also be determined by determining whether Japanese is used or English only.

In such a case, not only the simple field attribute but also the user's judgment is required. The result of this human judgment can be manually input and set so that it can be reflected in the field length of the converted database 32. Therefore, the database conversion unit 24 has this interface.

Therefore, step 124 performs the following processing. For example, if there are five fields in the data format conversion target database, the system administrator 28 prompts the terminal used by the system administrator 28 to input the field length. At this time, if the field attributes such as the current field length are displayed, the system administrator 28 determines and inputs an appropriate setting value while referring to the information. Then, the converted database 32 is generated based on this set value (step 13).
0).

As described above, according to the present embodiment, since the input from the outside is possible, it is possible to set the field length in consideration of more detailed human judgment.

In this embodiment, the system administrator 28 inputs from the terminal as a front end, but this input method is input from, for example, a definition file that holds field information created separately. The same effect can be obtained.

Embodiment 7 FIG . FIG. 7 is a flowchart showing the processing in the seventh embodiment according to the present invention in association with the configuration shown in FIG. The basic processing flow is
This is almost the same as each of the above embodiments.

By the way, while the data format conversion process is being performed, the other processes are put in a normal waiting state, and there is a possibility that the response of the normal online process is deteriorated. Therefore, in the present embodiment,
If the system is a multi-processor, make sure that only a specific processor performs the data format conversion processing, and reserves the other processors for the processing other than the data format conversion processing. It has a feature. As a result, the response of the processing other than the data format conversion processing can be maintained.

Therefore, in the present embodiment, as the next step of the step 120 for performing the data format conversion process of the database, if the system is a multiprocessor before the whole process is performed, the subsequent process is clearly indicated. Process for dynamically allocating to a specific processor (step 12)
5, 126). For example, when an interface of a system service used in a certain UNIX is used as an example, the conversion program to be executed is executed by using an interface such as processor_bind (conversion process name, execution CPU number); It is conceivable that the CPU is executed by specifying the execution CPU number of the existing process.

The method using such an interface is a function provided in an operating system that supports some multiprocessors, and if it is implemented based on an operating system that does not support it, Of course, you can extend the operating system to add features.

The database conversion according to the present embodiment is intended to save the existing database as it is and to perform the database conversion without stopping the online processing for the normal database. It is not preferable that the CPU of the CPU is consumed and the response of normal online processing is deteriorated. Therefore, by assigning this entire database conversion process to a specific processor,
Since the normal online processing can be executed by another processor, the response of the processing other than the data format conversion processing hardly deteriorates.

Embodiment 8. In the above-described seventh embodiment, when the system is a multiprocessor, the processing performed by each processor is divided and performed so that the response of the processing other than the data format conversion processing is maintained. The present embodiment is characterized in that the priority for executing the data format conversion process is set low. By doing so, the response of the processing other than the data format conversion processing can be maintained even in the single processor.

FIG. 8 is a flowchart showing the processing in the eighth embodiment according to the present invention in correspondence with the configuration shown in FIG. The basic processing flow is almost the same as that in each of the above embodiments. In the present embodiment,
By providing a process (step 127) for setting the priority of execution of the data format conversion process before performing the entire process, the response of the processes other than the data format conversion process is maintained. For example, taking the UNIX system call interface as an example, it is conceivable that the conversion program to be executed sets its own execution priority using an interface such as nice (execution priority).

Such an interface is often provided by many operating systems and can be easily realized. Or, without it, you could extend the operating system to add functionality.

As described above, the database conversion in this embodiment is intended to preserve the existing database as it is and to perform the database conversion without stopping the online processing for the normal database. Since such database conversion consumes a considerable amount of CPU, there is a possibility that the response such as normal online processing may be deteriorated. Therefore, if the entire database conversion process is set to a low priority and executed in advance, the normal online process is executed preferentially, and the data format conversion process is executed when the CPU has a margin. Therefore, the response of processes other than the data format conversion process is hardly degraded.

Ninth Embodiment FIG. 9 is a schematic configuration diagram of the information processing system in the present embodiment. The present system is characterized in that the configuration shown in FIG. 1 is further provided with an access recording unit 50 as an access recording unit that records the history of update access to the pre-conversion database 30 during the data format conversion process in the log file 52. I am trying. This makes it possible to achieve data consistency without invalidating the database access during the data format conversion process. That is, it is generally known that if the database access generated during the data format conversion processing is processed as it is, the data consistency cannot be obtained. The access recording unit 50 records the detected database access in the log file 52.

FIG. 10 is a flowchart showing the processing in the ninth embodiment according to the present invention in association with the configuration shown in FIG. The basic processing flow is almost the same as that in each of the above embodiments. The processing of the present embodiment will be described based on this figure. While the access to the database 32 is detected (step 100), the data format conversion processing is performed (steps 120, 13).
If there is an update access request to the database 30 in 0), the database 30 is not actually updated, but all the updated contents are recorded in the log file 52 (step 150). The recording may be performed by a method of recording the record before the update and the record after the update, similar to the method when the journaling of the normal file is performed, and the content of the original database 30 and the information in the log file 52 are recorded. From here, you can keep a record of all updates. Note that it is possible to stop the processing from the user and give priority to the data format conversion processing, but during the conversion processing, there is a risk that it may interfere with normal business, so here, the general user's Continue processing as is.

When the data format conversion processing is completed, the update access processing during the data format conversion processing, that is, the processing recorded in the log file 52 has not been performed on the databases 30 and 32 at this point. The recorded processing is reflected in the databases 30 and 32 (step 160).

In this way, according to the present embodiment,
Since the access recording unit 50 is provided and the update access during the data format conversion process is recorded in the log file 52, the consistency of the data in the databases 30 and 32 can be ensured and the normal online process is stopped. Can be run without

In the flowchart shown in FIG. 10, for convenience sake, the access recording process is described as the process after steps 120 and 130, but in reality, step 150, step 120, and This is performed in parallel with the processing of step 130.

Tenth Embodiment In the ninth embodiment, the history of database access during the data format conversion process is recorded in order to ensure data consistency. However, in the present embodiment, an application that accesses the database 32 is recorded. The feature of the present invention is that the operation of the program 26 is temporarily stopped to ensure data consistency. FIG. 11 is a flowchart showing the processing in the tenth embodiment of the present invention in association with the configuration shown in FIG. The processing in the present embodiment will be described based on this figure.

The present system executes the data format conversion process when detecting the access to the database 32. However, during the conversion process, when detecting the access to the database 32 from another application program 26 (step 100). ), The operation of the application program 26 requesting the access is temporarily stopped (step 105). When the end of the data format conversion process is detected (step 135), the application program 26 is restarted, and the stopped process is continued. The application program 26 can access the desired data converted into the new data format.

In this way, according to the present embodiment,
Data consistency can be achieved by suspending the execution of the application program 26 and waiting for access to the database.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram of an embodiment of an information processing system having a database conversion method according to the present invention.

FIG. 2 is a flowchart showing the processing in the first embodiment in association with the configuration shown in FIG.

FIG. 3 is a diagram showing a general configuration of a database.

FIG. 4 is a flowchart showing a process in a fourth embodiment according to the present invention in association with the configuration shown in FIG.

FIG. 5 is a flowchart showing a process according to a fifth embodiment of the present invention in association with the configuration shown in FIG.

FIG. 6 is a flowchart showing a process in a sixth embodiment of the present invention in association with the configuration shown in FIG.

FIG. 7 is a flowchart showing a process according to a seventh embodiment of the present invention in association with the configuration shown in FIG.

FIG. 8 is a flowchart showing a process according to an eighth embodiment of the present invention in association with the configuration shown in FIG.

FIG. 9 is a schematic configuration diagram of a ninth embodiment of an information processing system having a database conversion method according to the present invention.

FIG. 10 is a flowchart showing the processing in the ninth embodiment in association with the configuration shown in FIG. 9.

FIG. 11 is a flowchart showing the processing in the tenth embodiment of the present invention in association with the configuration shown in FIG.

FIG. 12 is a block diagram showing a conventional “migration method in an online processing system”.

FIG. 13 is a block diagram showing a conventional “migration method in an online processing system”.

FIG. 14 is a block diagram showing a conventional “migration method in an online processing system”.

FIG. 15 is a block diagram showing a conventional “migration method in an online processing system”.

FIG. 16 is a block diagram showing a conventional “dynamic change method of data items in record type data”.

[Explanation of symbols]

20 database management system, 22 database access unit, 24 database conversion unit, 26 application program, 28 system administrator, 30
Before conversion database, 32 After conversion database, 40
Database, 41, 42 table, 43-48
Records, 50 access records, 52 log files.

Claims (14)

[Claims] 1. A first database for storing data in a first data format, a data format detecting means for detecting access in a second data format, and a first data format in the first database. A data format conversion unit that performs a data format conversion process of converting data into a different second data format; and a second database that stores the converted data in the second data format. The database conversion method is characterized in that it is automatically generated when the access by the second data format is detected for the first time. 2. The database conversion method according to claim 1, wherein the data format conversion means converts the entire first database when an access in the second data format is detected for the first time. Database conversion method to be used. 3. The database conversion method according to claim 1, wherein the data format conversion means performs conversion in table units. 4. The database conversion method according to claim 1, wherein the data format conversion unit converts in record units. 5. The database conversion method according to claim 1, wherein the second database is hidden during a data format conversion process. 6. The database conversion method according to claim 1, further comprising storage area size determining means for determining a size of a storage area of data to be stored in the second database. 7. The database conversion method according to claim 6, wherein the storage area size determining unit has a function of automatically calculating and determining a size of a data storage area. 8. The database conversion method according to claim 6, wherein the storage area size determining unit has a setting value from the outside as a size of the data storage area. 9. The database conversion method according to claim 1, wherein the response of processing other than the data format conversion processing is maintained. 10. The database conversion method according to claim 9, wherein the data format conversion means performs a data format conversion process only by a specific processor in the case of a multiprocessor configuration. 11. The database conversion method according to claim 10, wherein a priority for executing the data format conversion process is set low. 12. The database conversion method according to claim 1, wherein data consistency is achieved during a data format conversion process. 13. The database conversion method according to claim 12, wherein an access recording unit that records a history of update access to the first database during a data format conversion process in a log file, and contents recorded in the log file. A means for reflecting in the second database, and a database conversion method comprising: 14. The database conversion method according to claim 12, wherein update access processing to the database during the data format conversion processing is prohibited.