Heterogeneous data migration method and device, equipment and storage medium

Abstract

The invention discloses a heterogeneous data migration method and device, equipment and a storage medium, and the method comprises the steps: packaging received query information into a query table object, the query information comprising a target library name, a table name and a filtering condition; acquiring a master-slave strategy, a target library migration state and a mapping relationship; converting the lookup table object into a target library acquisition request according to the mapping relation; and based on the master-slave strategy and the target library migration state, obtaining source data information in the original library according to the target library obtaining request, and migrating the source data to the target library. The technical problem that in the prior art, for massive and diversified databases, different query language and interface requirements are difficult to meet, and consequently data migration is limited can be solved.

Description

Technical Field

[0001] The present application relates to the field of data processing technology, and in particular to a heterogeneous data migration method, device, equipment and storage medium. Background Art

[0002] With the rapid development of science and technology, the database field has undergone tremendous changes. In the past, relational databases have long dominated the market and have won wide acclaim for their rigorous structure and powerful transaction processing capabilities. However, with the innovation of technology, the database field has also shown a diversified development trend. Today, various types of databases such as relational databases, document databases, graph databases, vector databases, key-value databases, spatial databases, etc. coexist and compete with each other, forming a diversified ecosystem. The emergence of this diversity not only meets the data management needs in different scenarios, but also promotes the continuous innovation and development of database technology.

[0003] At the same time, the popularity of Web applications and mobile devices has led to an explosive growth in the amount of data. These data are massive, diverse, and rapidly changing, which poses a severe challenge to traditional relational databases. When processing these data, relational databases often face performance bottlenecks and scalability issues, and cannot meet the rapid development needs of the business. Although NoSQL databases can better cope with the storage and access pressure of massive data with their flexible data models and powerful scalability, there are many types of NoSQL databases, and their query languages ​​and operation interfaces are also different, which brings certain difficulties to data migration and integration. Summary of the invention

[0004] The present application provides a heterogeneous data migration method, device, equipment and storage medium, which are used to solve the technical problem that the existing technology is difficult to meet the requirements of different query languages ​​and interfaces in the face of massive and diverse databases, resulting in limited data migration.

[0005] In view of this, the first aspect of the present application provides a heterogeneous data migration method, including:

[0006] Encapsulate the received query information into a query table object, wherein the query information includes a target library name, a table name, and a filtering condition;

[0007] Obtain the master-slave strategy, target database migration status and mapping relationship;

[0008] Converting the query table object into a target library acquisition request according to the mapping relationship;

[0009] Based on the master-slave strategy and the migration status of the target library, the source data information in the original library is obtained according to the target library acquisition request, and the source data is migrated to the target library.

[0010] Preferably, based on the master-slave strategy and the migration status of the target library, the source data information in the original library is obtained according to the target library acquisition request, and the source data is migrated to the target library, including:

[0011] Obtain source data information in the original database according to the target database acquisition request;

[0012] The source data information is stored in a table object in a table parsing manner to generate a source data table object;

[0013] Storing the target data of the target library into a table object in a table parsing manner to generate a target data table object;

[0014] Based on the master-slave strategy and the migration status of the target database, master-slave association mapping synchronization is performed according to the source data table object and the target data table object, and the source data is migrated to the target database.

[0015] Preferably, based on the master-slave strategy and the migration status of the target library, the source data information in the original library is obtained according to the target library acquisition request, and the source data is migrated to the target library, and then it also includes:

[0016] The target database is queried, and the query result is converted into a table object to obtain a result table object.

[0017] Preferably, based on the master-slave strategy and the migration status of the target library, the source data information in the original library is obtained according to the target library acquisition request, and the source data is migrated to the target library, and then it also includes:

[0018] Encapsulate the received interface update request into an update table object;

[0019] Based on the update table object, an update operation is performed on the data of the target library according to the original library, and the update operation includes adding, modifying and deleting.

[0020] A second aspect of the present application provides a heterogeneous data migration device, including:

[0021] A query encapsulation unit, used to encapsulate the received query information into a query table object, wherein the query information includes a target library name, a table name and a filtering condition;

[0022] An information acquisition unit, used to obtain the master-slave strategy, target database migration status and mapping relationship;

[0023] A form conversion unit, used for converting the query table object into a target library acquisition request according to the mapping relationship;

[0024] The data migration unit is used to obtain source data information in the original library according to the target library acquisition request based on the master-slave strategy and the migration status of the target library, and migrate the source data to the target library.

[0025] Preferably, the data migration unit is specifically used for:

[0026] Obtain source data information in the original database according to the target database acquisition request;

[0027] The source data information is stored in a table object in a table parsing manner to generate a source data table object;

[0028] Storing the target data of the target library into a table object in a table parsing manner to generate a target data table object;

[0029] Based on the master-slave strategy and the migration status of the target database, master-slave association mapping synchronization is performed according to the source data table object and the target data table object, and the source data is migrated to the target database.

[0030] Preferably, it also includes:

[0031] The query return unit is used to query the target library and convert the query result into a table object to obtain a result table object.

[0032] Preferably, it also includes:

[0033] An update encapsulation unit, used for encapsulating the received interface update request into an update table object;

[0034] A data updating unit is used to update the data of the target library according to the original library based on the update table object, and the update operation includes adding, modifying and deleting.

[0035] A third aspect of the present application provides a heterogeneous data migration device, the device comprising a processor and a memory;

[0036] The memory is used to store program code and transmit the program code to the processor;

[0037] The processor is used to execute the heterogeneous data migration method described in the first aspect according to the instructions in the program code.

[0038] A fourth aspect of the present application provides a computer-readable storage medium, wherein the computer-readable storage medium is used to store program code, and the program code is used to execute the heterogeneous data migration method described in the first aspect.

[0039] It can be seen from the above technical solutions that the embodiments of the present application have the following advantages:

[0040] In the present application, a heterogeneous data migration method is provided, including: encapsulating received query information into a query table object, the query information including a target library name, a table name and a filter condition; obtaining a master-slave strategy, a target library migration status and a mapping relationship; converting the query table object into a target library acquisition request according to the mapping relationship; based on the master-slave strategy and the target library migration status, obtaining source data information in the original library according to the target library acquisition request, and migrating the source data to the target library.

[0041] The heterogeneous data migration method provided by the present application can encapsulate the query information at the interface for receiving the query information, use the table object as a transfer, and realize the migration of data from the original database to the target database in combination with the mapping relationship between the data table and the table object in the database; the process is applicable to the migration of a variety of heterogeneous databases, has a certain universality, and can meet the needs of data migration between more databases. Therefore, the present application can solve the technical problem that the existing technology is difficult to meet the requirements of different query languages ​​and interfaces in the face of massive and diverse databases, resulting in limited data migration. BRIEF DESCRIPTION OF THE DRAWINGS

[0042] Figure 1 A schematic diagram of a process for heterogeneous data migration provided in an embodiment of the present application;

[0043] Figure 2 A schematic diagram of the structure of a heterogeneous data migration device provided in an embodiment of the present application;

[0044] Figure 3 A schematic diagram of the influence relationship between the source data table, the target data table and the table objects provided in the embodiment of the present application;

[0045] Figure 4 A schematic diagram of the data migration interaction process of heterogeneous databases in an application system provided in an embodiment of the present application;

[0046] Figure 5 A schematic diagram of a database update interaction process in an application system provided in an embodiment of the present application;

[0047] Figure 6 A schematic diagram of the connection relationship between the application system interaction modules provided for the application example of this application. DETAILED DESCRIPTION

[0048] In order to enable those skilled in the art to better understand the solution of the present application, the technical solution in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0049] For easier understanding, see Figure 1 , an embodiment of a heterogeneous data migration method provided by the present application includes:

[0050] Step 101: Encapsulate the received query information into a query table object, where the query information includes a target database name, a table name, and a filter condition.

[0051] In this embodiment, the database where the data to be migrated is located is taken as the original database, and the final database where the data needs to be migrated is taken as the target database; the query information can be used to find the corresponding target database and data table; however, different databases may require different query languages ​​and interfaces, so this embodiment directly encapsulates the query information into a table object, which can be compatible with queries of any type of database and facilitate data migration between databases.

[0052] Step 102: Obtain the master-slave strategy, target database migration status and mapping relationship.

[0053] The master-slave strategy refers to the replication strategy between the original library and the target library, where the master library refers to the original library and the slave library refers to the target library; the target library migration status also stores the migration status or process of the target library; the mapping relationship refers to the mapping relationship between the data table and the table object in the database, or it can be the mapping relationship between the synchronized original library and the target library data table. The master-slave strategy, the target library migration status and the mapping relationship can all be generated by the policy configuration scheme, and these policy schemes can be adaptively formulated according to actual conditions. This embodiment only provides examples and is not limited; and the policies based on these configurations can realize the conversion between the data table and the table object of the database, thereby universally migrating the data of heterogeneous databases without changing the query language and interface; it can greatly improve the efficiency of data migration.

[0054] Step 103: Convert the query table object into a target library acquisition request according to the mapping relationship.

[0055] Since the query table object is converted to a storage format to be compatible with different types of databases, the query table object needs to be reversed before data migration, and converted into a target database acquisition request; this allows subsequent source data acquisition operations.

[0056] Step 104: Based on the master-slave strategy and the target database migration status, the source data information in the original database is obtained according to the target database acquisition request, and the source data is migrated to the target database.

[0057] Furthermore, step 104 includes:

[0058] Obtain source data information in the original database according to the target database acquisition request;

[0059] Store the source data information into the table object in the form of table parsing to generate the source data table object;

[0060] Store the target data of the target library into the table object by table parsing to generate the target data table object;

[0061] Based on the master-slave strategy and the migration status of the target database, the master-slave association mapping is synchronized according to the source data table objects and the target data table objects, and the source data is migrated to the target database.

[0062] Based on the mapping relationship between the source data table and the table object, the source data table obtained from the original library can be converted into a table object to obtain the source data table object. The specific process is to parse the row-by-row data fields and column-by-column data fields of the source data table; then, through the mapping relationship between the source data table and the table object, the data is stored in the table object to obtain the source data table object.

[0063] For example, the source data table contains fields acc (account number, string type), phone_number (mobile phone number, numeric type), and send_name (sender name, string type), which are mapped to table object field names user, contact, and nick respectively. When the parsed field name is acc, the value is test, and it is stored in the table object data attribute in the form of user="test". When the parsed field name is phone_number, the value is 18912345678, and it is stored in the table object data attribute in the form of contact=18912345678. When the parsed field name is send_name, the value is xiaoming, and it is stored in the table object data attribute in the form of nick="xiaoming".

[0064] According to the above query information conversion table query table object situation, the subsequent source data migration still needs to reversely convert its corresponding source data table object into source data table data. The specific process is to traverse the attribute fields of the source data table object, one by one and one by one. When the key is parsed as user, this field in the mapping relationship is a string type. When splicing the oracle string, use acc as the field name, and use the string type for variable binding of the value; when the key is parsed as contact, this field in the mapping relationship is a numeric type. When splicing the oracle string, use phone_number as the field name, and use the numeric type for variable binding of the value; when the key is parsed as nick, this field in the mapping relationship is a string type. When splicing the oracle string, use send_name as the field name, and use the numeric type for variable binding of the value.

[0065] Based on the mapping relationship between the target data table and the table object of the target library, the target data of the target library can be stored in the table object to generate the target data table object. The specific process is to parse the row-by-row data fields and column-by-column data fields of the target data table in the target library; then, through the mapping relationship between the target data table and the table object, the data is stored in the table object to obtain the source data table object.

[0066] For example, the target data table contains fields ac (account number, string type), pn (mobile phone number, numeric type), sn (sender name, string type), which are mapped to table object field names user, contact, and nick respectively. When the parsed field name is ac, the value is test, and it is stored in the table object data attribute in the form of user="test". When the parsed field name is pn, the value is 18912345678, and it is stored in the table object data attribute in the form of contact=18912345678. When the parsed field name is sn, the value is xiaoming, and it is stored in the table object data attribute in the form of nick="xiaoming".

[0067] Similarly, the generated target data table object also needs to be reversed in the subsequent data migration process to obtain the target table data. The specific process is to loop through the table object data attribute fields, one by one and one by one; when the key is parsed as user, this field in the mapping relationship is of string type, and when constructing the BSON object, ac is used as the field name, and the value is bound to the variable using the string type; when the key is parsed as contact, this field in the mapping relationship is of numeric type, and when constructing the BSON object, pn is used as the field name, and the value is bound to the variable using the numeric type; when the key is parsed as nick, this field in the mapping relationship is of string type, and when constructing the BSON object, sn is used as the field name, and the value is bound to the variable using the numeric type.

[0068] Based on the above method, the source data table and table object of the original library, and the target data table and table object of the target library are mapped. Figure 3; Then, based on the master-slave strategy and the migration status of the target database, the relationship between the source data table and the target data table can be synchronized, and data migration can be achieved through table traversal. At the same time, the database switch can be automatically completed to meet the offline standard of the original database. The master-slave strategy can determine that the data is read from the master database and written to the slave database. The migration status of the target database can reflect the progress of the migration process. Before the data of the specified table is migrated, the changes in historical data need to be synchronized with the master and slave at the same time. After the migration is completed, only the target database needs to be written; the migration status of the target database can reflect this status at any time, so as to control the progress of the migration. In order to improve the efficiency of migration, the row and column traversal can be performed in a one-table-one-entry or one-table-multiple-process manner. There is no limitation here. As long as the migration of the source data can be completed quickly and the master-slave relationship can be switched quickly, it can be done.

[0069] For practical application examples, see Figure 4 ,Data migration between databases is actually an interactive process between the application end, interface module, policy configuration module, distributor, converter, source database and target database. Both the interface information and the acquired source data need to be converted into table objects first, and then reversely converted into request information that meets the processing requirements. The table object is used as an intermediate state to realize data migration between different types of databases, so as to be compatible with the data migration and query requirements of various types of databases.

[0070] Furthermore, step 104 further includes:

[0071] Query the target database and convert the query results into a table object to obtain a result table object.

[0072] When the source data is completely migrated to the target database, you can query the target database, convert the query results into table objects, obtain the result table objects and return them to the application layer on the interface. If the data has not been migrated, you need to query the source data table of the original database and convert the data into a table object structure, and then convert it back to the migration target database format during data migration; obtain the target database query primary key, query whether the data exists in the target database, and if not, write the data into the target database to complete the data migration; traverse all data until the data migration is completed.

[0073] Furthermore, step 104 further includes:

[0074] Encapsulate the received interface update request into an update table object;

[0075] Based on the update table object, the data in the target database is updated according to the original database. The update operation includes adding, modifying and deleting.

[0076] See also Figure 5The data update operation process in the database in this embodiment is similar to the data migration process. Based on the same intermediate state of the table object, both the request information at the interface and the data table obtained in the middle need to be converted to the table object and the request reverse conversion; the update operation can be to modify and delete the data in the database, or to add new data; these operations are all considered to be data table update operations. During the data migration process, the business is still in service, and the data will continue to change during this period. The addition of data update operations is to ensure data consistency and keep the data on both the source and target databases synchronized.

[0077] If the source database is denoted as DB-s and the target database is denoted as DB-d, then in the actual development application system, the connection relationship between each end can be referred to Figure 6 The interface module can realize the universal encapsulation of database table operations, and the application can implement the addition, deletion, modification and query of the specified library table through API interface calls; the policy configuration module can be responsible for setting the master-slave replication strategy, tracking the migration process of the storage table, and synchronizing the mapping relationship between the source table and the target database table; the distributor can determine the request issuance strategy based on the master-slave strategy and table migration status of the policy configuration; the converter can convert the database operation request into the corresponding database operation, convert the database return data, and convert the database record row into a custom structure according to the table mapping relationship.

[0078] If it is the data update phase, when the data of the target data table of the target database has been migrated, the DB-d converter is called; when the data of the target data table has not been migrated, the DB-s converter and the DB-d converter are called at the same time. It can be understood that all the results are finally returned to the interface module in the form of table objects and presented to the application layer.

[0079] This application applies the heterogeneous data migration method to the Oracle library that stores mailbox accounts. The original secure mailbox uses Oracle as the mailbox account repository to store mailbox account information, departments, organizations, group messaging groups, system configurations, and other information. In the general direction of the company's de-IOE, these data need to be migrated to Mongodb. The solution of this application has transformed the application and used the above operation solution to achieve hot migration of data. While ensuring that the business is not interrupted, all data is gradually and smoothly migrated to Mongodb, completing the overall switch of the database.

[0080] The solution of this application is a data migration method based on table objects. When completing the data migration of a table, the master-slave relationship of the table is switched, making the database switching process smoother. Mainly, the solution of this application not only realizes non-stop service migration, but also does not require the writing of complex migration tools, and realizes automatic switching of data after the migration is completed; this can realize managed migration, reduce manual management, and reduce the complexity of migration.

[0081] The heterogeneous data migration method provided in the embodiment of the present application can encapsulate the query information at the interface for receiving the query information, use the table object as a transfer, and combine the mapping relationship between the data table and the table object in the database to realize the migration of data from the original library to the target library; this process is applicable to the migration of a variety of heterogeneous databases, has a certain universality, and can meet the needs of data migration between more databases. Therefore, the embodiment of the present application can solve the technical problem that the existing technology is difficult to meet the requirements of different query languages ​​and interfaces in the face of massive and diverse databases, resulting in limited data migration.

[0082] For easier understanding, see Figure 2 The present application provides an embodiment of a heterogeneous data migration device, including:

[0083] The query encapsulation unit 201 is used to encapsulate the received query information into a query table object, where the query information includes a target database name, a table name, and a filtering condition;

[0084] The information acquisition unit 202 is used to acquire the master-slave strategy, the target database migration status and the mapping relationship;

[0085] A form conversion unit 203, used to convert the query table object into a target library acquisition request based on the mapping relationship;

[0086] The data migration unit 204 is used to obtain source data information in the original database according to the target database acquisition request based on the master-slave strategy and the target database migration status, and migrate the source data to the target database.

[0087] Furthermore, the data migration unit 204 is specifically configured to:

[0088] Obtain source data information in the original database according to the target database acquisition request;

[0089] Store the source data information into the table object in the form of table parsing to generate the source data table object;

[0090] Store the target data of the target library into the table object by table parsing to generate the target data table object;

[0091] Based on the master-slave strategy and the migration status of the target database, the master-slave association mapping is synchronized according to the source data table objects and the target data table objects, and the source data is migrated to the target database.

[0092] Furthermore, it also includes:

[0093] The query return unit 205 is used to query the target library and convert the query result into a table object to obtain a result table object.

[0094] Furthermore, it also includes:

[0095] The update encapsulation unit 206 is used to encapsulate the received interface update request into an update table object;

[0096] The data updating unit 207 is used to update the data of the target library according to the original library based on the update table object. The update operation includes adding, modifying and deleting.

[0097] The present application also provides a heterogeneous data migration device, the device comprising a processor and a memory;

[0098] The memory is used to store the program code and transmit the program code to the processor;

[0099] The processor is used to execute the heterogeneous data migration method in the above method embodiment according to the instructions in the program code.

[0100] The present application also provides a computer-readable storage medium, which is used to store program code, and the program code is used to execute the heterogeneous data migration method in the above method embodiment.

[0101] In the several embodiments provided in the present application, it should be understood that the disclosed devices and methods can be implemented in other ways. For example, the device embodiments described above are only schematic. For example, the division of the units is only a logical function division. There may be other division methods in actual implementation, such as multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. Another point is that the mutual coupling or direct coupling or communication connection shown or discussed can be through some interfaces, indirect coupling or communication connection of devices or units, which can be electrical, mechanical or other forms.

[0102] The units described as separate components may or may not be physically separated, and the components shown as units may or may not be physical units, that is, they may be located in one place or distributed on multiple network units. Some or all of the units may be selected according to actual needs to achieve the purpose of the solution of this embodiment.

[0103] In addition, each functional unit in each embodiment of the present application may be integrated into one processing unit, or each unit may exist physically separately, or two or more units may be integrated into one unit. The above-mentioned integrated unit may be implemented in the form of hardware or in the form of software functional units.

[0104] If the integrated unit is implemented in the form of a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present application is essentially or the part that contributes to the prior art or all or part of the technical solution can be embodied in the form of a software product. The computer software product is stored in a storage medium, including a number of instructions for executing all or part of the steps of the method described in each embodiment of the present application through a computer device (which can be a personal computer, server, or network device, etc.). The aforementioned storage medium includes: U disk, mobile hard disk, read-only memory (full name in English: Read-Only Memory, English abbreviation: ROM), random access memory (full name in English: Random Access Memory, English abbreviation: RAM), disk or optical disk and other media that can store program codes.

[0105] As described above, the above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit them. Although the present application has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present application.

Claims

1. A heterogeneous data migration method, characterized in that: include: Encapsulate the received query information into a query table object, wherein the query information includes a target library name, a table name, and a filtering condition; Obtain the master-slave strategy, target database migration status and mapping relationship; Converting the query table object into a target library acquisition request according to the mapping relationship; Based on the master-slave strategy and the migration status of the target library, the source data information in the original library is obtained according to the target library acquisition request, and the source data is migrated to the target library.

2. The heterogeneous data migration method according to claim 1, characterized in that: The method of acquiring source data information in the original database based on the master-slave strategy and the migration status of the target database according to the target database acquisition request and migrating the source data to the target database includes: Obtain source data information in the original database according to the target database acquisition request; The source data information is stored in a table object in a table parsing manner to generate a source data table object; Storing the target data of the target library into a table object in a table parsing manner to generate a target data table object; Based on the master-slave strategy and the migration status of the target database, master-slave association mapping synchronization is performed according to the source data table object and the target data table object, and the source data is migrated to the target database.

3. The heterogeneous data migration method according to claim 1, characterized in that: Based on the master-slave strategy and the migration status of the target database, the source data information in the original database is obtained according to the target database acquisition request, and the source data is migrated to the target database, and then it also includes: The target database is queried, and the query result is converted into a table object to obtain a result table object.

4. The heterogeneous data migration method according to claim 1, characterized in that: Based on the master-slave strategy and the migration status of the target database, the source data information in the original database is obtained according to the target database acquisition request, and the source data is migrated to the target database, and then it also includes: Encapsulate the received interface update request into an update table object; Based on the update table object, an update operation is performed on the data of the target library according to the original library, and the update operation includes adding, modifying and deleting.

5. A heterogeneous data migration device, characterized in that: include: A query encapsulation unit, used to encapsulate the received query information into a query table object, wherein the query information includes a target library name, a table name and a filtering condition; An information acquisition unit, used to obtain the master-slave strategy, target database migration status and mapping relationship; A form conversion unit, used for converting the query table object into a target library acquisition request according to the mapping relationship; The data migration unit is used to obtain source data information in the original library according to the target library acquisition request based on the master-slave strategy and the migration status of the target library, and migrate the source data to the target library.

6. The heterogeneous data migration device according to claim 5, characterized in that: The data migration unit is specifically used for: Obtain source data information in the original database according to the target database acquisition request; The source data information is stored in a table object in a table parsing manner to generate a source data table object; Storing the target data of the target library into a table object in a table parsing manner to generate a target data table object; Based on the master-slave strategy and the migration status of the target database, master-slave association mapping synchronization is performed according to the source data table object and the target data table object, and the source data is migrated to the target database.

7. The heterogeneous data migration device according to claim 5, characterized in that: Also includes: The query return unit is used to query the target library and convert the query result into a table object to obtain a result table object.

8. The heterogeneous data migration device according to claim 5, characterized in that: Also includes: An update encapsulation unit, used for encapsulating the received interface update request into an update table object; A data updating unit is used to update the data of the target library according to the original library based on the update table object, and the update operation includes adding, modifying and deleting.

9. A heterogeneous data migration device, characterized in that: The device comprises a processor and a memory; The memory is used to store program codes and transmit the program codes to the processor; The processor is used to execute the heterogeneous data migration method described in any one of claims 1-4 according to the instructions in the program code.

10. A computer-readable storage medium, characterized in that: The computer-readable storage medium is used to store program code, and the program code is used to execute the heterogeneous data migration method according to any one of claims 1 to 4.

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