Service · Bespoke software

System and database migration

A familiar scenario: a warehouse program written twenty years ago in Delphi on a Firebird database, its author long since busy elsewhere, running on a Windows Server 2012 box that no longer gets security patches. It works until the day it does not. We move systems like this to new versions, different database engines or the cloud, and while the company keeps trading there is no second chance. Preparation therefore takes the lion's share of the work, and the cut-over happens remotely at a time you approve.

Dress rehearsal
before the real move
Window
calculated from measurements
Fallback
tested in advance
Reconciliation
of totals and row counts

Included in this service

Success is won long before cut-over night: the switch itself is short compared with the groundwork behind it.

Talk the scope through with an engineer

Inventory

The components in scope, their dependencies, data locations, and the integrations, reports and overnight scripts will break once the database address changes.

Migration plan

Steps in order, an estimated duration for each and decision points where we deliberately choose to carry on or roll back.

Data conversion

Mapping types, character encodings and structures, for example from Firebird or an old MS SQL instance to PostgreSQL. Polish characters stored in Windows-1250 in legacy databases are a classic trap.

Dress rehearsals

A full migration of a data copy on a test environment, stopwatch in hand. Run one nearly always turns up something unexpected; run two seldom does.

Fallback plan

Written and rehearsed steps to restore the old system should a serious issue appear after switchover.

Verification

Checksums, row totals and sampling of critical figures: unpaid receivables, contractor balances and stock levels as at the cut-over date.

How we work together

Preparation time depends on data volume and the number of dependencies. The switchover is usually planned for a weekend, and its length becomes clear once the trial run is done.

01

Assessment

Size of the data, linked systems and the longest outage your operations can tolerate, such as whether the warehouse works on Saturdays.

02

Dress rehearsal

An end-to-end pass over a copy, timing every step and producing a list of script fixes.

03

Switchover

Within the approved window, by the practised runbook, with a single named engineer online throughout.

04

Observation

For an agreed period we watch the system closely, while the old one stays available for comparison and read access.

Do not switch the old system off the day after migration. Leave it running, or at least readable, for a few weeks. Something that did not come across, or came across wrong, nearly always surfaces. Remember too that accounting records must be kept for years, and update your record of processing activities if personal data has changed location.

Questions and answers

Only the dress rehearsal gives a firm figure, because it measures timing on your real data. The cut-over is usually planned to start on Friday evening so everything is running by Monday morning.

For some systems, yes: through live data replication and a brief cut-over at the end. It is more expensive and complex, so it makes sense where even an hour offline means real losses, such as a busy online shop. Most companies manage fine with a weekend.

For migrating data, usually not: we work with the database itself and rebuild the logic from the data and from talking to users. It is trickier if you want to keep developing the old program. Then it is worth first establishing with a lawyer who holds the rights, and it often turns out that writing a new module is the sensible route.

Yes, that is a common choice. We choose the data centre region with you so that it matches your GDPR documentation, and you add the cloud provider to your records as a processor.

Let us plan your migration

Describe the source, the destination and the outage you could live with. We will begin with a dress rehearsal on a copy of your data.

Hours
Mon-Fri 8:00-18:00 CET, reply within one working day
Meetings
Online via Teams or Google Meet

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