MODERNIZE · MIGRATION & MODERNIZATION
Modernize With Traceability and Controlled Risk.
Protect business continuity while replacing or extending legacy database, warehouse and integration workloads. Bassirah plans migrations workload by workload, proves equivalence with reconciliation evidence and builds rollback decision points into every cutover.
WHEN TO ENGAGE
When Migration Becomes a Priority
Migrations rarely fail because of the target technology. They fail because of hidden dependencies, untested assumptions and cutovers with no way back.
Legacy platforms are reaching end of life
Support, licensing or hardware constraints force a move, and you need a plan that respects business deadlines.
Workloads have outgrown the current platform
Performance, concurrency or cost no longer fit, and a modern analytical or operational platform is needed.
You want to reduce lock-in
You are moving toward open table formats, federated access or community platforms to gain portability.
Previous migrations stalled
Earlier attempts lost momentum or confidence because results could not be proven equivalent.
WHAT WE DO
Included Activities
Inventory
- Catalog of databases, schemas, pipelines, jobs, reports and consumers in scope
- Dependency mapping across upstream sources and downstream applications
- Identification of unused or redundant objects that need not move
Workload segmentation
- Grouping of workloads by complexity, criticality and dependency
- Migration waves that deliver value early and contain risk
- Candidate pilot workload selection
Compatibility assessment
- SQL dialect, data type, function and feature differences between source and target
- Connector, driver and adapter compatibility for the versions in use
- Gaps that need redesign rather than translation
Mapping and conversion
- Schema, data type and object mapping specifications
- Query, procedure and transformation conversion approach
- Data movement method per workload: bulk, incremental or change data capture where supported
Parallel run
- Source and target running side by side on agreed workloads
- Comparison of results, timings and behaviour under realistic load
- Issue log with resolution tracking
Reconciliation
- Row counts, aggregates, checksums and business-rule checks agreed with data owners
- Evidence recorded per table, report or workload
- Sign-off by accountable owners
Rollback and cutover strategy
- Cutover runbook with timing, roles and communication plan
- Explicit go and no-go criteria and rollback decision points
- Post-cutover monitoring and decommissioning plan for the legacy platform
WHAT YOU RECEIVE
Example Deliverables
| Deliverable | What it contains | Who uses it |
|---|---|---|
| Migration plan | Inventory, waves, sequence, dependencies, resourcing and risks | Program leadership and delivery teams |
| Compatibility assessment | Feature and dialect gaps, conversion approach and redesign items | Architects and engineers |
| Mapping specifications | Object, schema and data type mapping for each workload | Engineering teams |
| Validation evidence | Reconciliation results, parallel-run comparisons and owner sign-offs | Data owners, audit and risk |
| Cutover checklist | Step-by-step cutover runbook, roles, timings and communications | Operations and change management |
| Rollback decision points | Go and no-go criteria and the procedure to revert at each point | Program leadership and operations |
ENGAGEMENT PHASES
How the Engagement Works
- AssessBuild the inventory, map dependencies and complete the compatibility assessment. Confirm what moves, what is redesigned and what is retired.
- PlanSegment workloads into waves, define reconciliation rules with data owners and agree cutover and rollback criteria.
- PilotMigrate a representative pilot workload end to end to prove the method, tools and reconciliation approach.
- Migrate in wavesConvert, move and validate each wave, with parallel runs where agreed.
- Cut overExecute the cutover runbook with go and no-go checkpoints and a tested rollback path.
- Stabilize and decommissionMonitor the new platform, close remaining issues, hand over to operations and plan legacy decommissioning.
MIGRATION PATTERNS
Common Migration Paths
Every migration is assessed individually. These are patterns we frequently plan for.
| From | To | Key considerations |
|---|---|---|
| Legacy or proprietary data warehouse | ClickHouse, Trino OSS or Starburst over open lakehouse storage | SQL dialect differences, workload concurrency, BI tool compatibility |
| Proprietary relational database | PostgreSQL | Procedural code conversion, data types, extensions, application drivers |
| Hand-coded SQL and scheduled scripts | dbt Core & dbt OSS projects | Model structure, testing, lineage and adapter support for the target engine |
| Siloed operational and analytical stores | Federated access with Trino OSS or Starburst | Connector support, security model, performance expectations for federated queries |
| Legacy file or object storage | MinIO AIStor object storage | S3 API behaviour, data movement windows, application changes |
| Self-managed NoSQL clusters on outdated versions | Current Apache Cassandra or MongoDB Community releases | Upgrade path, data model review, driver compatibility |
Federated access does not remove the need for access controls, modeling, metadata and governance. These are part of the plan.
Planning a move off a legacy warehouse or database?
Start with an assessment of what moves, what changes and what retires.
TECHNOLOGY COVERAGE
Migration Targets We Support
Partner-led targets where commercial capabilities, licensed features or vendor-backed support are required.
Community targets supported independently by Bassirah engineering.
Scope of migration support.
Feature compatibility between source and target platforms is assessed per engagement and is not assumed. Bassirah migration services for community platforms are independent engineering and do not include upstream vendor support, vendor security fixes or vendor escalation. Migrations to partner-led platforms are subject to each vendor’s licensing and entitlements.
PREREQUISITES
What We Need From You
- Access to source systems, metadata and representative data, through your approved process
- Named data owners who can agree reconciliation rules and sign off results
- Business calendar constraints: freeze periods, peak seasons and reporting deadlines
- Target platform environments, or an implementation engagement to create them
- Application owners for systems that read from or write to the source
- A change management contact for cutover approvals and communications
Migration & Modernization FAQ
How do you prove the migrated data is correct?
Through reconciliation rules agreed with your data owners, such as row counts, aggregates, checksums and business-rule checks. Results are recorded as evidence and signed off per workload.
Can we migrate without downtime?
It depends on the source, target, data volumes and change rates. We assess this per workload and design the cutover to minimize disruption, with clear rollback decision points. We do not promise zero downtime.
Do we have to migrate everything at once?
No. We segment workloads into waves, starting with a pilot, so value and confidence build gradually.
What if some features do not exist on the target platform?
The compatibility assessment identifies these early. Each gap is either redesigned, handled by an adjacent component or recorded as a known limitation before migration starts.
Can you help after cutover?
Yes. Stabilization is part of the engagement, and the platform can then move to your operations team or a Bassirah managed services agreement.
Related Solutions
Migrate With Evidence, Not Assumptions
Tell us what you are moving from and to. We will scope an assessment that defines waves, validation and rollback.