FORM 2
THE PATENTS ACT, 1970
(39 of 1970)
&
THE PATENT RULES, 2003
COMPLETE SPECIFICATION (See Section 10 and Rule 13)
Title of invention: METHOD AND SYSTEM FOR DATA MIGRATION
Applicant
Tata Consultancy Services Limited
A company Incorporated in India under the Companies Act, 1956
Having address:
Nirmal Building, 9th floor,
Nariman point, Mumbai 400021,
Maharashtra, India
Preamble to the description
The following specification particularly describes the invention and the manner in which it is to be performed.

TECHNICAL FIELD [001] The disclosure herein generally relates to the field of data migration and more specifically, to a system and method for data migration for a relational database.
BACKGROUND
[002] Data migration is the process of moving data from one system to another. While this might seem pretty straightforward, it involves a change in storage and database or application. Organizations need to chart a well-planned strategy by conferring with all business stakeholders to outline the scope of data migration, the timeline, and the availability of resources. The strategy should be in alignment with business goals to ensure seamless migration. Choosing an effective, ready to use solution for organizational data migration is vital since building a tool is complex and time-consuming.
[003] In the computing field, data transformation is the process of converting data from one format or structure into another format or structure. It is a fundamental aspect of most data integration and data management tools. In a typical scenario where information needs to be shared, data is extracted from the source application, transformed into another format, and then loaded into the target application or data warehouse. Depending on the nature of the integration scenario, data may need to be transformed i.e. processed, converted, merged, aggregated, enriched, or filtered. Usually, the data transformation can be divided into various steps which are applicable as needed based on the complexity of the transformation required.
[004] In order to organizations’ systems upgrade, the data migration is required. In such scenario, an entity needs to be migrated as an atomic unit to achieve data consistency in the target system. In the current systems, mapping design performs data migration for a single data store in the target system without considering other related data store from same entity. Further, most of the arrangement where mappings are moving data sequentially and independently. In this independent mapping design execution, the data consistency in the target system

can arise if some records migration fails. This could potentially result into a customer without policy information, a partial/incomplete policy, payment history, and active policies without customer.
SUMMARY
[005] Embodiments of the disclosure present technological improvements as solutions to one or more of the above-mentioned technical problems recognized by the inventors in conventional systems. For example, in one embodiment, a method and system for data migration for a relational database is provided.
[006] In one aspect, a processor-implemented method for data migration for a relational database is provided. The method includes one or more steps such as retrieving, via an input/output interface, data from a group of two or more related source tables to migrate the data to a corresponding a group of two or more related target tables, wherein the group of two or more related source tables comprising one parent table having relation with one or more dependent child tables in a predefined logical tree format, mapping, via one or more hardware processors, each of the two or more related source tables to corresponding each of the two or more related target tables based on one or more predefined data attributes resulting in a set of two or more mappings, grouping, via the one or more hardware processors, the set of two or more mappings based on predefined relations within the two or more related source tables and the two or more related target tables to form an entity, migrating, via the one or more hardware processors, the entity to at least one of the two or more related target tables, wherein the migrated entity is reconciled between the source table and the target table to ensue completion of migration.
[007] In another aspect, a system for data migration for a relational database is provided. The system includes an input/output interface configured to retrieve data from a group of two or more related source tables to migrate the data to a corresponding a group of two or more related target tables, wherein the group of two or more related source tables comprising one parent table having relation with one or more dependent child tables in a predefined logical tree format, one or more hardware processors and at least one memory storing a plurality of

instructions, wherein the one or more hardware processors are configured to execute the plurality of instructions stored in the at least one memory.
[008] Further, the system is configured to map each of the two or more related source tables to corresponding each of the two or more related target tables based on one or more predefined data attributes resulting in a set of two or more mappings, group the set of two or more mappings based on predefined relations within the two or more related source tables and the two or more related target tables to form an entity, and migrate the entity to at least one of the two or more related target tables, wherein the migrated entity is reconciled between the source table and the target table to ensue completion of migration.
[009] In yet another aspect, one or more non-transitory machine-readable information storage mediums are provided comprising one or more instructions, which when executed by one or more hardware processors causes a method for data migration for a relational database is provided. The method includes one or more steps such as retrieving, via an input/output interface, data from a group of two or more related source tables to migrate the data to a corresponding a group of two or more related target tables, wherein the group of two or more related source tables comprising one parent table having relation with one or more dependent child tables in a predefined logical tree format, mapping, via one or more hardware processors, each of the two or more related source tables to corresponding each of the two or more related target tables based on one or more predefined data attributes resulting in a set of two or more mappings, grouping, via the one or more hardware processors, the set of two or more mappings based on predefined relations within the two or more related source tables and the two or more related target tables to form an entity, migrating, via the one or more hardware processors, the entity to at least one of the two or more related target tables, wherein the migrated entity is reconciled between the source table and the target table to ensue completion of migration.
[010] It is to be understood that the foregoing general descriptions and the following detailed description are exemplary and explanatory only and are not restrictive of the invention, as claimed.

BRIEF DESCRIPTION OF THE DRAWINGS
[011] The accompanying drawings, which are incorporated in and constitute a part of this disclosure, illustrate exemplary embodiments and, together with the description, serve to explain the disclosed principles:
[012] FIG. 1 illustrates a block diagram of a system for data migration for a relational database, according to an embodiment of the present disclosure.
[013] FIG. 2 is a schematic diagram of to illustrate relation among a parent table with one or more dependent child tables, according to an embodiment of the present disclosure.
[014] FIG. 3 is a schematic diagram to illustrate data migration of a group of source tables to a group of target tables, according to an embodiment of the present disclosure.
[015] FIG. 4 is a functional block diagram of the system for data migration for the relational database, according to an embodiment of the present disclosure.
[016] FIG. 5 is a flow diagram to illustrate a processor-implemented method for data migration for a relational database, in accordance with some embodiments of the present disclosure.
DETAILED DESCRIPTION OF EMBODIMENTS [017] Exemplary embodiments are described with reference to the accompanying drawings. In the figures, the left-most digit(s) of a reference number identifies the figure in which the reference number first appears. Wherever convenient, the same reference numbers are used throughout the drawings to refer to the same or like parts. While examples and features of disclosed principles are described herein, modifications, adaptations, and other implementations are possible without departing from the scope of the disclosed embodiments.
[018] The embodiments herein provide a method and system for data migration for a relational database. It has been observed that in a typical scenario where information needs to be shared, the data is extracted from the source application, transformed into another format, and then loaded into the target application or data warehouse. Depending on the nature of the integration scenario,

the data may need to be transformed i.e. processed, converted, merged, aggregated, enriched, or filtered. It would be appreciated that the data migration is required during system upgrade, software change, business acquisition. In such scenarios, an occurrence of an entity (Ex: a customer and its related information as dependent chain records in related tables such as Policy, Payments) should be moved completely as a single unit to achieve data integrity in the target system. Failing to migrate the entire occurrence of the entity will have adverse impact on the target system end users experience e.g. a customer profile without policy information, partial/incomplete policy, payment history and active policies without customer.
[019] Herein, the system is configured to develop a model for entity migration that can be treated as valid when all related information migrates completely or not at all. To achieve data atomicity between different mappings, herein the proposed invention groups them together. An orchestration layer of the system is configured to manage communication between different mappings, and sequencing of mappings. Further, the data is inserted in parent-child order to achieve referential integrity, and a single transaction across all mappings to ensure smooth entity migration and data atomicity.
[020] Referring now to the drawings, and more particularly to FIG. 1 through 5, where similar reference characters denote corresponding features consistently throughout the figures, there are shown preferred embodiments and these embodiments are described in the context of the following exemplary system and/or method.
[021] FIG. 1 illustrates an exemplary system (100) for data migration for a relational database, in accordance with an example embodiment. Although the present disclosure is explained considering that the system (100) is implemented on a server, it may be understood that the system (100) may comprise one or more computing devices (102), such as a laptop computer, a desktop computer, a notebook, a workstation, a cloud-based computing environment and the like. It will be understood that the system (100) may be accessed through one or more input/output interfaces 104-1, 104-2... 104-N, collectively referred to as I/O interface (104). Examples of the I/O interface (104) may include, but are not limited

to, a user interface, a portable computer, a personal digital assistant, a handheld device, a smartphone, a tablet computer, a workstation, and the like. The I/O interface (104) are communicatively coupled to the system (100) through a network (106).
[022] In an embodiment, the network (106) may be a wireless or a wired network, or a combination thereof. In an example, the network (106) can be implemented as a computer network, as one of the different types of networks, such as virtual private network (VPN), intranet, local area network (LAN), wide area network (WAN), the internet, and such. The network (106) may either be a dedicated network or a shared network, which represents an association of the different types of networks that use a variety of protocols, for example, Hypertext Transfer Protocol (HTTP), Transmission Control Protocol/Internet Protocol (TCP/IP), and Wireless Application Protocol (WAP), to communicate with each other. Further, the network (106) may include a variety of network devices, including routers, bridges, servers, computing devices, storage devices. The network devices within the network (106) may interact with the system (100) through communication links.
[023] The system (100) supports various connectivity options such as BLUETOOTH®, USB, ZigBee, and other cellular services. The network environment enables connection of various components of the system (100) using any communication link including Internet, WAN, MAN, and so on. In an exemplary embodiment, the system (100) is implemented to operate as a stand-alone device. In another embodiment, the system (100) may be implemented to work as a loosely coupled device to a smart computing environment. Further, the system (100) comprises at least one memory (110) with a plurality of instructions, one or more databases (112), and one or more hardware processors (108) which are communicatively coupled with the at least one memory to execute a plurality of modules (114) therein. The components and functionalities of the system (100) are described further in detail.
[024] In one embodiment, the system (100) is configured to retrieve data from a group of two or more related source tables to migrate the data to a

corresponding a group of two or more related target tables. Herein, the group of two or more related source tables comprising one parent table having relation with one or more dependent child tables in a predefined logical tree format. Further, the group of two or more related target tables comprising one parent table having relation with one or more dependent child tables in a predefined logical tree format as illustrated in FIG. 2.
[025] It is to be noted that an entity is a group of one or more related records from different tables forming a single meaning unit. Database transactions are often composed of multiple statements. Atomicity guarantees that each transaction is treated as a single unit, which either succeeds completely, or fails. Furthermore, the consistency ensures that a transaction movement can only bring the database from one valid state to another.
[026] Referring FIG. 3, a schematic diagram (300) to illustrate data migration of a group of source tables to a group of target tables, according to an embodiment of the present disclosure. Herein, the system (100) is configured to map each of the two or more related source tables to corresponding each of the two or more related target tables based on one or more predefined data attributes resulting in a set of two or more mappings. It would be appreciated that the mapping design is the process of identifying, mapping and linking the data attributes from the source system to the target system i.e. specifying how the target data store (table) may be populated from data in one or more source data stores. In addition to mapping transformation rules define how source fields are modified, joined, filtered, aggregated etc. to produce the final desired output (code for execution). Usually a mapping consists of one or more source system table and a single target system table.
[027] Usually, mapping design performs data migration for a single data store in the target system without considering other related data store from same entity. In one example, wherein mappings are moving data for customer, policy, and payment sequentially and independently. Herein, migration of customer records in batches and on completing one move the system performs next mapping to migrate all policy records in batches. In this independent mapping design execution, the data

inconsistency in target database can arise if some record migration fails. This could potentially result into a customer without policy information, partial/incomplete policy and payment history and active policies without customer.
[028] Referring FIG. 4, a functional block diagram (400) to illustrate the system (100) for data migration, according to an embodiment of the present disclosure. Herein, the orchestration layer of the system (100) act as a wrapper and co-ordinate data migration for customer entity for all types of mapping. The data migration flow may happen as the orchestration layer may initiate transaction at step (202). For parent-child mapping, a single table from source may be inserted in a target. For this table, key value (C101) may be retained and used in child mapping as filter at step (204). Further, for child mapping, tables from source policy eligible for filter value (C101) will be fetched and inserted in the target. For related source tables, key values (C101, & P101, and P102) may be retained and used in dependent child tables mapping as filter at step (206). Furthermore, for dependent child tables mapping tables from source eligible for filter value (C101 & P101, P102) may be fetched and inserted in the target at step (208). It would be appreciated that if the record insertion in the target tables completes successfully then transaction may be committed, and flow may continue for next entity (C102). However, if table insertion in the target tables fails at any step then transaction will be reverted, and flow may continue for next entity (C102). Therefore, at the end of each execution an entity is either fully migrated to the target database or fails completely to achieve entity atomicity and data integrity.
[029] It would be appreciated that the system (100) herein is configured to create the logical tree of two or more related source tables having corresponding two or more related target tables. Herein, the logical tree comprises a group of tables from a root node to a leaf node. The logical tree comprises nodes from root node to a leaf node for each of the two or more related source tables. Further, the system (100) is configured to sequence each of the group of tables of the created logical tree to create an orchestration layer for managing the entity migration. Herein, the logical tree starting from the root node and ending towards the leaf node. Furthermore, each sequenced node is migrated to the target table iteratively, wherein

the migrated data is reconciled between the source table and the target table to root level to ensue completion of data migration. The data migration is treated successful when the parent table along with each of the one or more dependent child tables migrates completely. It is to be noted that an occurrence of the entity reverts back if the parent table and at least one of the one or more dependent child tables has a failure during migration.
[030] Referring FIG. 5 to illustrate a processor-implemented method (500) for data migration for a relational database, in accordance with an example embodiment.
[031] Initially, at the step (502), retrieving, via an input/output interface, data from a group of two or more related source tables to migrate the data to a corresponding a group of two or more related target tables. Herein, the group of two or more related source tables comprising one parent table having relation with one or more dependent child tables in a predefined logical tree format. Further, the group of two or more related target tables comprising one parent table having relation with one or more dependent child tables in a predefined logical tree format.
[032] At the next step (504), mapping each of the two or more related source tables to corresponding each of the two or more related target tables based on one or more predefined data attributes resulting in a set of two or more mappings. The number of nodes of the logical tree are segregated at more than one level based on the relationship of the parent table with the one or more dependent child tables.
[033] At the next step (506), grouping the set of two or more mappings based on predefined relations within the two or more related source tables and the two or more related target tables to form an entity. Herein, the grouping comprising steps of creating the logical tree of two or more related source tables having corresponding two or more related target tables and sequencing each of the group of tables of the created logical tree to create an orchestration layer for managing the entity migration. Further, the logical tree comprises a group of tables from a root node to a leaf node and the logical tree starts from the root node and ending towards the leaf node.
[034] At the next step (508), migrating the entity to at least one of the two

or more related target tables, wherein the migrated entity is reconciled between the source table and the target table to ensue completion of migration. It is to be noted that the migration of the entity is treated successful when the parent table along with each of the one or more dependent child tables migrates completely. Furthermore, an occurrence of the entity reverts back if the parent table and at least one of the one or more dependent child tables has a failure during migration. Herein, the one parent table and corresponding the one or more dependent child tables are migrated as a single atomic unit to the group of two or more related target tables.
[035] The written description describes the subject matter herein to enable any person skilled in the art to make and use the embodiments. The scope of the subject matter embodiments is defined by the claims and may include other modifications that occur to those skilled in the art. Such other modifications are intended to be within the scope of the claims if they have similar elements that do not differ from the literal language of the claims or if they include equivalent elements with insubstantial differences from the literal language of the claims.
[036] The embodiments of present disclosure herein address unresolved problem of data migration for a relational database, most of the scenarios where information needs to be shared, data is extracted from the source application, transformed into another format, and then loaded into the target application or data warehouse. The embodiments herein provide a method and system to develop a model for entity migration that can be treated as valid when all related information migrates completely or not at all. To achieve data atomicity between different mappings, herein the proposed invention groups them together. An orchestration layer of the system is configured to manage communication between different mappings, and sequencing of mappings. Further, the data is inserted in parent-child order to achieve referential integrity, and a single transaction across all mappings to ensure smooth entity migration and data atomicity.
[037] It is to be understood that the scope of the protection is extended to such a program and in addition to a computer-readable means having a message therein; such computer-readable storage means contain program-code means for implementation of one or more steps of the method, when the program runs on a

server or mobile device or any suitable programmable device. The hardware device can be any kind of device which can be programmed including e.g., any kind of computer like a server or a personal computer, or the like, or any combination thereof. The device may also include means which could be e.g., hardware means like e.g., an application-specific integrated circuit (ASIC), a field-programmable gate array (FPGA), or a combination of hardware and software means, e.g., an ASIC and an FPGA, or at least one microprocessor and at least one memory with software modules located therein. Thus, the means can include both hardware means, and software means. The method embodiments described herein could be implemented in hardware and software. The device may also include software means. Alternatively, the embodiments may be implemented on different hardware devices, e.g., using a plurality of CPUs.
[038] The embodiments herein can comprise hardware and software elements. The embodiments that are implemented in software include but are not limited to, firmware, resident software, microcode, etc. The functions performed by various modules described herein may be implemented in other modules or combinations of other modules. For the purposes of this description, a computer-usable or computer readable medium can be any apparatus that can comprise, store, communicate, propagate, or transport the program for use by or in connection with the instruction execution system, apparatus, or device.
[039] The illustrated steps are set out to explain the exemplary embodiments shown, and it should be anticipated that ongoing technological development will change the manner in which particular functions are performed. These examples are presented herein for purposes of illustration, and not limitation. Further, the boundaries of the functional building blocks have been arbitrarily defined herein for the convenience of the description. Alternative boundaries can be defined so long as the specified functions and relationships thereof are appropriately performed. Alternatives (including equivalents, extensions, variations, deviations, etc., of those described herein) will be apparent to persons skilled in the relevant art(s) based on the teachings contained herein. Such alternatives fall within the scope of the disclosed embodiments. Also, the words

“comprising,” “having,” “containing,” and “including,” and other similar forms are intended to be equivalent in meaning and be open ended in that an item or items following any one of these words is not meant to be an exhaustive listing of such item or items, or meant to be limited to only the listed item or items. It must also be noted that as used herein and in the appended claims, the singular forms “a,” “an,” and “the” include plural references unless the context clearly dictates otherwise.
[040] Furthermore, one or more computer-readable storage media may be utilized in implementing embodiments consistent with the present disclosure. A computer-readable storage medium refers to any type of physical memory on which information or data readable by a processor may be stored. Thus, a computer-readable storage medium may store instructions for execution by one or more processors, including instructions for causing the processor(s) to perform steps or stages consistent with the embodiments described herein. The term “computer-readable medium” should be understood to include tangible items and exclude carrier waves and transient signals, i.e., be non-transitory. Examples include random access memory (RAM), read-only memory (ROM), volatile memory, nonvolatile memory, hard drives, CD ROMs, DVDs, flash drives, disks, and any other known physical storage media.
[041] It is intended that the disclosure and examples be considered as exemplary only, with a true scope of disclosed embodiments being indicated by the following claims.

We Claim:
1. A processor-implemented method (500) comprising steps of:
retrieving (502), via an input/output interface, data from a group of two or more related source tables to migrate the data to a corresponding a group of two or more related target tables, wherein the group of two or more related source tables comprising one parent table having relation with one or more dependent child tables in a predefined logical tree format;
mapping (504), via one or more hardware processors, each of the two or more related source tables to corresponding each of the two or more related target tables based on one or more predefined data attributes resulting in a set of two or more mappings; grouping (506), via the one or more hardware processors, the set of two or more mappings based on predefined relations within the two or more related source tables and the two or more related target tables to form an entity; and
migrating (508), via the one or more hardware processors, the entity to at least one of the two or more related target tables, wherein the migrated entity is reconciled between the source table and the target table to ensue completion of migration.
2. The processor-implemented method (500) of the claim 1, wherein the group of two or more related target tables comprising one parent table having relation with one or more dependent child tables in the predefined logical tree format.
3. The processor-implemented method (500) of the claim 1, wherein the grouping comprising steps of;
creating, via the one or more hardware processors, the logical tree of two or more related source tables having corresponding two or more related target tables, wherein the

logical tree comprises a group of tables from a root node to a leaf node; and
sequencing, via the one or more hardware processors, each of the group of tables of the created logical tree to create an orchestration layer for managing the entity migration, wherein the logical tree starting from the root node and ending towards the leaf node.
4. The processor-implemented method (500) of the claim 1, wherein the migration of the entity is treated successful when an occurrence of the parent table along with related data from each of the one or more dependent child tables migrates completely.
5. The process-implemented method (500) of the claim 1, wherein an occurrence of the entity reverts back if the parent table or one of the one or more corresponding dependent child tables has a failure during migration.
6. The processor-implemented method (500) of claim 1, wherein the occurrence of the parent table and corresponding the one or more dependent child tables are migrated as a single atomic unit to the group of two or more related target tables.
7. The processor-implemented method (500) of claim 1, wherein the
number of nodes of the logical tree are segregated at more than one level
based on the relationship of the parent table with the one or more
dependent child tables.
8. A system (100) comprising:
an input/output interface (104) to retrieve data from a group of two or more related source tables to migrate the data to a corresponding a group of two or more related target tables, wherein the group of

two or more related source tables comprising one parent table having
relation with one or more dependent child tables in a predefined
logical tree format;
one or more hardware processors (108);
a memory (110) in communication with the one or more hardware
processors (108), wherein the one or more hardware processors
(108) are configured to execute programmed instructions stored in
the memory (110), to:
map each of the two or more related source tables to corresponding each of the two or more related target tables based on one or more predefined data attributes resulting in a set of two or more mappings;
group the set of two or more mappings based on predefined relations within the two or more related source tables and the two or more related target tables to form an entity; and migrate the entity to at least one of the two or more related target tables, wherein the migrated entity is reconciled between the source table and the target table to ensue completion of migration.
9. The system (100) of the claim 8, wherein the grouping comprising steps of;
creating, via the one or more hardware processors, the logical tree of two or more related source tables having corresponding two or more related target tables, wherein the logical tree comprises a group of tables from a root node to a leaf node; and
sequencing, via the one or more hardware processors, each of the group of tables of the created logical tree to create an orchestration layer for managing the entity migration,

wherein the logical tree starting from the root node and ending towards the leaf node.
10. A non-transitory computer readable medium storing one or more
instructions which when executed by one or more processors on a
system, cause the one or more processors to perform method
comprising:
retrieving, via an input/output interface, data from a group of two or more related source tables to migrate the data to a corresponding a group of two or more related target tables, wherein the group of two or more related source tables comprising one parent table having relation with one or more dependent child tables in a predefined logical tree format;
mapping, via one or more hardware processors, each of the two or more related source tables to corresponding each of the two or more related target tables based on one or more predefined data attributes resulting in a set of two or more mappings;
grouping, via one or more hardware processors, the set of two or more mappings based on predefined relations within the two or more related source tables and the two or more related target tables to form an entity; and
migrating, via the one or more hardware processors, the entity to at least one of the two or more related target tables, wherein the migrated entity is reconciled between the source table and the target table to ensue completion of migration.
11. The non-transitory computer readable medium of the claim 10, wherein
the grouping comprising steps of;
creating, via the one or more hardware processors, the logical tree of two or more related source tables having corresponding two or more related target tables, wherein the

logical tree comprises a group of tables from a root node to a leaf node; and
sequencing, via the one or more hardware processors, each of the group of tables of the created logical tree to create an orchestration layer for managing the entity migration, wherein the logical tree starting from the root node and ending towards the leaf node.