Here’s a real enterprise-grade Oracle migration checklist (used for AIX → RHEL, on-prem → cloud, or platform modernization). It is structured the way large banks, telecoms, and ERP environments execute migrations safely.

1. Governance & project readiness

Business alignment

• ☐ Migration scope clearly defined (DB only / full stack / apps included)
• ☐ Downtime window agreed (RTO/RPO targets defined)
• ☐ Critical business processes identified
• ☐ Stakeholders and approvers mapped

Project controls

• ☐ Migration strategy approved (GoldenGate / RMAN / Data Pump)
• ☐ Rollback strategy documented and tested
• ☐ Change management approvals (CAB) completed
• ☐ Risk register created

2. Source system assessment (AIX / legacy)

Oracle environment

• ☐ Oracle version & patch level documented
• ☐ Database size (datafiles, redo, temp) analyzed
• ☐ Character set verified (prefer AL32UTF8)
• ☐ Endianness identified (AIX = Big Endian)

Workload analysis

• ☐ AWR baseline captured (peak + off-peak)
• ☐ Top SQL queries identified
• ☐ Wait events analyzed
• ☐ Batch windows mapped

Dependencies

• ☐ Application integrations mapped (ERP, APIs, ETL)
• ☐ External jobs (cron, Control-M, scripts)
• ☐ Linked servers / DB links identified

3. Target architecture design (RHEL / Linux)

Infrastructure

• ☐ Server sizing validated (CPU, RAM, IOPS)
• ☐ Storage design confirmed (ASM / XFS / NVMe / SAN)
• ☐ Network bandwidth for replication confirmed

Oracle setup

• ☐ Oracle version compatibility confirmed
• ☐ Grid Infrastructure installed (if RAC/ASM)
• ☐ HugePages configured
• ☐ Kernel parameters tuned (sysctl.conf)

HA/DR design

• ☐ Data Guard design (if required)
• ☐ RAC decision (single vs cluster)
• ☐ Backup strategy (RMAN on Linux)

4. Migration strategy selection

Choose based on downtime requirement:

• ☐ Data Pump (low complexity, high downtime)
• ☐ RMAN cross-platform (medium complexity)
• ☐ GoldenGate (near-zero downtime – enterprise standard)

5. Data migration preparation

Schema readiness

• ☐ Primary keys exist on all tables
• ☐ Unsupported objects identified
• ☐ LOB handling validated
• ☐ Materialized views strategy defined

Pre-seeding data

• ☐ RMAN backup or Data Pump export completed
• ☐ Target database restored successfully
• ☐ Initial data consistency validated

6. Replication setup (if GoldenGate used)

Source (AIX)

• ☐ Extract process configured
• ☐ Archive log mode enabled
• ☐ Supplemental logging enabled

Target (RHEL)

• ☐ Replicat configured
• ☐ Trail files processing verified
• ☐ Initial sync completed

Validation

• ☐ Lag monitoring enabled
• ☐ Transaction consistency verified
• ☐ Conflict detection rules defined

7. Application readiness

Compatibility

• ☐ JDBC/OCI drivers tested
• ☐ Connection strings updated in test
• ☐ Timezone alignment verified
• ☐ Character encoding consistency checked

Code validation

• ☐ PL/SQL procedures tested
• ☐ Shell scripts updated (AIX → Linux commands)
• ☐ File path changes validated

8. Performance benchmarking

• ☐ AWR baseline captured on AIX
• ☐ Load testing on RHEL completed
• ☐ SQL execution plans compared
• ☐ I/O latency measured
• ☐ CPU scaling validated (NUMA awareness)

9. Cutover planning

Pre-cutover checklist

• ☐ Final replication lag = 0
• ☐ All stakeholders on standby
• ☐ Change freeze implemented
• ☐ Backup taken immediately before cutover

Cutover steps

• ☐ Stop application writes on source
• ☐ Final sync completed
• ☐ Switch traffic (DNS / load balancer / TNS)
• ☐ Validate transactions in target system

10. Rollback plan (mandatory)

• ☐ Source system kept intact
• ☐ Reverse replication plan (if needed)
• ☐ Application fallback tested
• ☐ DNS rollback procedure ready
• ☐ Decision point defined (go/no-go)

11. Post-migration validation

Data integrity

• ☐ Row count validation
• ☐ Financial reconciliation (if applicable)
• ☐ Critical tables verified

Application validation

• ☐ End-to-end business flows tested
• ☐ Integration systems verified
• ☐ Batch jobs running correctly

Performance checks

• ☐ AWR comparison (before vs after)
• ☐ CPU, memory, I/O monitoring
• ☐ Query performance stability

12. Optimization phase

• ☐ Gather new optimizer statistics
• ☐ Adjust SGA/PGA sizing
• ☐ Tune redo logs / I/O subsystem
• ☐ Enable compression if applicable
• ☐ Revisit partitioning strategy

13. Operations & monitoring setup

• ☐ Enterprise monitoring (OEM / Prometheus / Grafana)
• ☐ Alerting configured
• ☐ Backup jobs scheduled
• ☐ DR drills planned
• ☐ Access control reviewed (security hardening)

14. Decommissioning legacy system

• ☐ AIX system kept in read-only mode (initial period)
• ☐ Final sign-off from business
• ☐ Archive backup stored securely
• ☐ Decommission plan approved
• ☐ Licensing cleanup (if applicable)

15. Common enterprise pitfalls

⚠ Skipping workload baseline (AWR)
⚠ Ignoring hidden batch jobs
⚠ Underestimating network lag in GoldenGate
⚠ Missing primary keys for replication
⚠ Not testing rollback
⚠ Carrying AIX tuning assumptions to Linux

16. Golden rule

“Successful Oracle migration is not about moving data — it is about preserving business continuity under a new architecture.”