Moving From One Database Platform to Another Without Losing History
Database migration moves your data from one database engine or platform to another — commonly when a vendor discontinues support, a licence becomes too costly, or performance limits are reached — with schema conversion and a tested cutover.
An Engine-Level Move, Not a Software Switch
This is a technical, engine-level move — from one database platform to another, such as an ageing on-premise SQL Server instance to a managed cloud PostgreSQL service — rather than a switch between different business applications. The schema, the data types and often parts of the query logic have to be converted, not just copied.
Common Reasons Businesses Migrate
- A database platform is being discontinued or no longer receives security updates from its vendor
- Licence costs on the current platform have grown out of proportion to what the database is used for
- The current platform has reached a performance ceiling as data volume has grown
- Moving from on-premise hardware to a managed cloud service to reduce operational upkeep
How a Migration Is Planned
Schema Conversion
Table structures, data types and constraints are translated to the target platform's equivalents, since not every feature has a direct match across engines.
A Test Migration First
The move is run against a copy before it touches the live database, so conversion issues are found and fixed without any risk to what is currently running.
A Defined Cutover Window
A planned period, usually outside working hours, during which the live system switches from the old platform to the new one.
A Rollback Plan
A tested way to revert to the old platform if the cutover uncovers a problem, agreed before the cutover begins rather than improvised during it.
What Migrating Without a Plan Puts at Risk
A migration attempted without a tested rollback tends to surface its problems at the worst possible time — mid-cutover, with the old platform already partly decommissioned. Query behaviour that looked identical in testing can diverge under real production load, and an application that assumed a feature specific to the old platform can fail in ways that only show up once live traffic hits it.
Frequently asked questions
How long does a database sit unavailable during the cutover?
It depends on data volume and the target platform, but the window is planned and communicated in advance, and is generally scheduled outside your business's working hours to minimise disruption.
What if something breaks after we have already switched to the new platform?
A rollback plan is prepared and tested before cutover specifically for this — the old platform is kept available for an agreed period after the switch, not decommissioned immediately.
Does application code that reads from the database need to change?
Sometimes, depending on how directly your applications depend on features specific to the old platform. We identify this during the schema conversion stage, well before the cutover, so there are no surprises on the day.
Can this be done in phases rather than all at once?
For some setups, yes — migrating less critical databases first to prove the process before moving the ones your business depends on most. For a single tightly coupled system, a single planned cutover is usually cleaner.
What decides the cost of a database migration?
The size and complexity of the schema, how much the target platform differs from the current one, and how much application code depends on platform-specific behaviour.
Who has access to the new database once migration is complete?
Whoever you designate — access and administration credentials are handed over to you, held in a secrets store rather than embedded in code, and not retained by us beyond any agreed support period.
Tell us what you need.
Send a short brief and one of our engineers will come back to you — usually the same day.
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- We reply the same working day
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