Oracle migration to the Cloud: the complete strategy (baseline, performance, costs, licenses, run)
- Jean-Michel Alluguette – OP&S
- Dec 18, 2025
- 4 min read
Updated: Dec 18, 2025
Migrating an Oracle database to the Cloud (OCI, AWS…) is not just “moving” a database.
The real risks — and the real gains — hinge on four key areas:
baseline , configuration , licenses , post-migration management .
The good news: with a simple method, you can quickly obtain:
+30 to +70% performance improvement on certain treatments
an optimized CPU/RAM ratio ,
license savings (reduced use of expensive packages),
a reduction in backup costs through volume reduction.
Here is a pragmatic, reproducible framework, applicable to Oracle Database “alone”, or to your ERP (JD Edwards, E-Business Suite).
Migration checklist (summary in 10 seconds)
Baseline (comparable windows)
Volumetrics
Licenses/options
Key parameters
Validation before/after
Run tracking
1) Before migrating: build a factual baseline (without manual benchmarking)
Most cloud projects become complicated because we don't know how to answer a simple question after the switchover:
“Is it better than before… and why?”
You do not need to organize a benchmark over several weeks if you already have a history of metrics.
The key is to compare comparable windows :
Standard working day (e.g., Tuesday 10am–12pm)
Peak activity (e.g., closing time)
Batch window (if ERP)
Minimum baseline to capture
Overall workload (DB Time / activity)
Distribution of waiting times (I/O, concurrency, configuration…)
CPU/memory usage
I/O latency (if available)
Top treatments / consumer requests
Volume + growth (DATA / index / TEMP / UNDO)
Objective: to have an indisputable “before”, in order to validate the “after” in equivalent time slots.
2) The biggest hidden lever: reducing volume before migration
Reducing the volume before migration is not “cleaning”.
That's direct ROI:
less data to move,
less cloud storage
Less backup time,
lower recurring costs.
Typical Actions (Oracle BDD)
Identify fast-growing objects (tables / indexes)
Purging/archiving (according to business rules)
Checking "technical" tables that are growing (logs, history, staging)
Review of TEMP/UNDO spaces (actual size vs. inherited size)
ERP case studies (JDE in particular)
Purging and archiving are often a massive accelerator:
reduction of historical tables,
management of “backup” tables (often oversized),
and sometimes recourse to mechanisms like Advanced Compression (to be treated as a separate licensing issue).
3) Licenses: secure and optimize before moving the problem
A cloud migration is the best time to do a “reality vs. contract” review.
Otherwise, you migrate expensive options… and you continue to pay (or you take a risk).
The 3 most common topics
Diagnostic + Tuning Packs : often “used” via tools, sometimes without governance.
Active Data Guard (or replication strategies): useful, but expensive; consider alternatives depending on the objective.
GoldenGate : very powerful, but needs to be economically justified (and compared to migration services depending on the case).
AWS example: Active Data Guard vs DMS (depending on the objective)
If your main need is data migration/replication for a failover or for BI needs, AWS DMS type approaches can be considered depending on constraints (object types, synchronization requirements, delta tolerance, etc.).
OCI equivalent?
OCI offers migration/replication services and approaches (depending on your choices: Data Guard/GoldenGate/OCI Services), but the key message remains the same:
The replication architecture is chosen based on the actual need , not out of habit.
Important: do not “take an option” because it is there — link it to a clear use case + a cost.
“No commitment – limited scope – action plan presentation”
4) Settings & configuration: what the Cloud resets (and which breaks performance)
The Cloud doesn't magically "degrade" Oracle.
The damage almost always stems from invisible differences:
sizing of redo logs, TEMP, UNDO
statistics strategy
self-behavior (jobs/advisors)
memory/concurrency settings
storage / I/O profile different
Before/after checks: the shortlist that avoids 80% of surprises
Redo logs: switch size / frequency
TEMP/UNDO: sizing + pressure during peaks
Memory (SGA/PGA): consistency with the cloud instance type (CPU/RAM ratio)
Statistics: Collection method and window
I/O latency: comparisons under equivalent conditions
Top waits: unexpected appearance of a “Configuration” or “Concurrency” class
5) Optimize the CPU/RAM ratio (and avoid oversizing)
Many cloud migrations are oversized “for security reasons”.
That's understandable... but expensive.
The rational approach:
measure actual usage before migration,
choose a consistent cloud target,
validate after switching over.
adjust quickly.
This cycle is the one that generates sustainable gains:
performance,
stability,
and recurring savings.
6) Post-Oracle migration validation: compare “before/after” on the same windows
The validation must be factual.
We're replaying the same windows as the baseline:
standard working day,
peak activity,
batch (if applicable).
Then we check:
the overall load,
the distribution of waits,
the top treatments,
and writing behaviors (redo / checkpoints).
Goal: to avoid the situation where “everything works” but more slowly, and where the diagnosis starts too late.
7) After the migration: the true value is in the run (regular review)
Migration is a moment. The run is a duration.
Without regular review, you will find:
slow drifts,
volumetric growth,
oversizing,
options reactivated
Backup costs are rising again.
Recommended review
enhanced monitoring 2 to 4 weeks post-switchover
then monthly/quarterly review:
performance trends,
volumetry,
resource usage (FinOps),
options/licenses,
priority actions.
Conclusion
A successful Oracle migration to the Cloud is not simply “we moved the database”.
It is :
a clear baseline,
controlled volume,
a clean licensing strategy,
a validated configuration before/after
and regular pilot running.
This framework allows for concrete gains: +30 to +70% performance , optimization of the CPU/RAM ratio , reduction of license and backup costs.
Have you migrated your Oracle environment to the Cloud (or are you considering it)?
A 1-month OP&S PoC allows for:
to capture the current state of your Oracle databases,
to identify configuration or performance deviations,
and to calmly prepare for your future developments.
About the author
Jean-Michel Alluguette is the founder of OP&S, a software dedicated to Oracle and ERP (JD Edwards / E-Business Suite) environments to manage performance, costs (FinOps) and security/licenses.
Do you want a factual analysis of your Oracle databases? → Request a free 1-month PoC.
Comments