DATA MIGRATIONDATA MIGRATION

Applied Database IIApplied Database II

DEFINITIONDEFINITION

Data migration is a set of activities that moves data from one or more legacy systems to a new application

Data migration can be in level of : Machine Application Data

BackgroundBackground

Updating the user-interface of Updating the user-interface of application, adding or updating the application, adding or updating the function of an application in the same function of an application in the same machine with same datamachine with same data

Migrating to new machineMigrating to new machine Restructuring data in an applicationRestructuring data in an application Updating application, restructuring tables, Updating application, restructuring tables,

and moving to new machine.and moving to new machine.

Background ActivitiesBackground Activities

Detail Activity plan for each phase Identify Resources Define Roles and Responsibilities Identify the Migration Tool

Background ActivitiesBackground Activities

Identify Scope of Automated Migration Identify the Data Preparation/Cleanup

Needs Identify Cross Reference Tables Migration Validation Strategy Define Procedure for setting up Master

Codes

Background ActivitiesBackground Activities

Prepare Data Extraction Tool Prepare Data Volume Analysis Tool Prepare Data Mappings

Background ActivitiesBackground Activities

Build Cross Reference Tables Preparing Data Preparation Queries Preparing Business Rules Validation

Tools Prepare Migration Validation Tools

Background ActivitiesBackground Activities

Document Scope Document Migration Strategy Document Data Preparation Operational

Procedures Document Migration Validation

Operational Procedures Document Quality Procedures Exception Reporting

StepsSteps

In principle, the migration of a system In principle, the migration of a system should not interfere with operation of should not interfere with operation of system. system.

Steps should be done is Steps should be done is Migration planningMigration planning MigratingMigrating Migration documentationMigration documentation Acceptance with UserAcceptance with User

Managerial ConsiderationManagerial Consideration

Phased or “Big Bang”?Phased or “Big Bang”? ExpectationExpectation RollbackRollback ScalabilityScalability ReplicationReplication

Phased or “Big Bang”?Phased or “Big Bang”?

Migrating all at once orMigrating all at once or Moving data over one piece at a timeMoving data over one piece at a time Some considerations :Some considerations :

How much data there is to migrateHow much data there is to migrate The amount of effort for a big bangThe amount of effort for a big bang

ExpectationsExpectations

How long will the migration take?How long will the migration take? How many internal resources must one How many internal resources must one

commit?commit? For what period of time?For what period of time? What is the level of expertise needed What is the level of expertise needed

from external sources?from external sources? What is the cost?What is the cost?

Rollback Rollback

What happens if the data migration fails?What happens if the data migration fails? Using existing transcation rollback Using existing transcation rollback

functionality or having capacity to design functionality or having capacity to design and build a new one?and build a new one?

Providing an additional layer of securityProviding an additional layer of security Helps reducing development costsHelps reducing development costs

Scalability Scalability

Is our current system going to support Is our current system going to support our growth plan in the next years?our growth plan in the next years?

What if we purchase another company What if we purchase another company and want to migrate their data into our and want to migrate their data into our systemsystem

ReplicationReplication

What happens in case of disaster or What happens in case of disaster or irrecoverable system failure?irrecoverable system failure?

Migrating data to a backup system at the Migrating data to a backup system at the same time as a new target system?same time as a new target system?

Migration planningMigration planning

For dataFor data Table structure of older application (table Table structure of older application (table

specification), should not re-type but drawn specification), should not re-type but drawn from definitions of existing systemsfrom definitions of existing systems

Table structure of new applicationTable structure of new application Mapping of each field from the old to the Mapping of each field from the old to the

new table and rulesnew table and rules Utilities are required to perform the data Utilities are required to perform the data

migration migration

Migration planningMigration planning

For Applications:For Applications: List of functions available on the old List of functions available on the old

applicationapplication List of functions available on a new List of functions available on a new

applicationapplication Old and new mapping functionality, with the Old and new mapping functionality, with the

necessary records necessary records

Migration planningMigration planning

For MachinesFor Machines Characteristics of a new engine for Characteristics of a new engine for

applications that run on old machinesapplications that run on old machines Things that should be done because the Things that should be done because the

change machinechange machine Utilities required Utilities required

Migration Migration Implementation Implementation

All data should be recorded in volumeAll data should be recorded in volume Data migration can often be assisted with Data migration can often be assisted with

tools andtools and Examples of planning documents and Examples of planning documents and

implementation of migration can be seen implementation of migration can be seen in the attached document in the attached document

DocumentationDocumentation

Catatan : • Field (Nama, type, length) tabel asal tidak diketik, tetapi diambil dari

dokumentasi sistem!• Pada kolom “Aturan” disebutkan aturan pemindahan data, apakah “apa

adanya” (hanya boleh jika field asal dan tujuan identik), ataukah harus dilakukan transformasi

• Jika lebar dan type field tidak sama, maka Kolom “Aturan” harus diisi dengan jelas