Oracle to Amazon Aurora PostgreSQL Migration with AWS DMS and SCT
A financial services company is migrating its Oracle database to Amazon Aurora PostgreSQL. The database runs a critical batch processing job every night that updates millions of rows. The company needs the migration to minimize downtime and ensure data integrity. Which AWS service should the database specialist use to perform the migration?
Quick Answer
The answer is AWS Database Migration Service (AWS DMS) with ongoing replication from Oracle to Aurora PostgreSQL. This is correct because DMS’s change data capture (CDC) capability continuously replicates live transactions from the source Oracle database to the target Aurora PostgreSQL after the initial full load, allowing the nightly batch job to keep running with minimal interruption and ensuring transactional consistency for data integrity. On the AWS Certified Database Specialty DBS-C01 exam, this scenario tests your understanding of near-zero-downtime migration strategies, often contrasting DMS with CDC against offline tools like native dump-and-load or AWS SCT alone, which require application downtime. A common trap is choosing AWS SCT only, but SCT handles schema conversion, not ongoing data replication. Remember the memory tip: “DMS with CDC keeps the data flowing while the batch keeps going.”
⚠ Common exam trap
Many candidates confuse AWS DMS with ETL tools like Glue or Data Pipeline, assuming any data movement service can handle live migrations, but only DMS provides the transactional consistency and CDC required for near-zero-downtime database migrations.
Answer choices
Why each option matters
Answer the question above first, then reveal the full breakdown to understand why each option is right or wrong.
Correct answer & explanation
✓
AWS Database Migration Service (AWS DMS) with ongoing replication from Oracle to Aurora PostgreSQL
AWS DMS with ongoing replication (change data capture, CDC) is the correct choice because it enables a near-zero-downtime migration by continuously replicating changes from the source Oracle database to the target Aurora PostgreSQL while the source remains fully operational. After the initial full load, DMS applies ongoing transactions, allowing you to cut over with minimal interruption. This directly addresses the requirement to minimize downtime for the nightly batch job and ensures data integrity through transactional consistency.
Answer analysis
Option-by-option breakdown
For each option: why learners choose it and why it is or isn't the right answer here.
- ✓
AWS Database Migration Service (AWS DMS) with ongoing replication from Oracle to Aurora PostgreSQL
Why this is correct
AWS DMS can perform a one-time migration and then use ongoing replication to keep the target in sync with the source, minimizing downtime.
- ✗
AWS Data Pipeline to export data from Oracle and import into Aurora PostgreSQL
Why it's wrong here
Data Pipeline is not designed for database migrations and does not support ongoing replication.
- ✗
AWS Schema Conversion Tool (AWS SCT) to convert the schema and then use native PostgreSQL tools to migrate data
Why it's wrong here
AWS SCT converts schema but does not handle ongoing replication; native tools may require significant downtime.
- ✗
AWS Glue to extract data from Oracle and load into Aurora PostgreSQL
Why it's wrong here
AWS Glue is an ETL service, not optimized for database migrations with minimal downtime.
Go deeper
Related to this question
About these practice questions
One of 1,663 original DBS-C01 practice questions on Courseiva, each with a full explanation and wrong-answer analysis — not exam dumps or protected exam content. Learn why practice questions differ from exam dumps →
Same concept, more angles
4 more ways this is tested on DBS-C01
These questions test the same concept from different angles. Work through them to make sure you can recognise it however the exam phrases it.
Variation 1. A company is migrating a 3 TB Oracle database to Amazon Aurora PostgreSQL. The database has a heavy OLTP workload with many small transactions. The migration must have minimal downtime. Which TWO strategies should the company use? (Choose two.)
hard- A.Convert the database to Amazon Aurora MySQL instead.
- B.Create an Aurora read replica from the Oracle database.
- ✓ C.Use AWS DMS with ongoing replication to capture and apply changes.
- D.Use AWS Schema Conversion Tool (SCT) to convert the schema.
- ✓ E.Set the target database to Amazon Aurora PostgreSQL.
Why C: AWS DMS with ongoing replication (CDC) is the correct strategy because it allows continuous capture and application of changes from the source Oracle database to the target Aurora PostgreSQL, enabling minimal downtime during migration. The heavy OLTP workload with many small transactions is well-suited for DMS's change data capture, which can handle high-volume transactional changes efficiently.
Variation 2. A company is migrating a large Oracle database to Amazon Aurora PostgreSQL. They need to minimize downtime and validate data consistency after migration. Which THREE steps should they include in their migration plan? (Choose THREE.)
hard- A.Create multiple Aurora Replicas for read scaling during migration.
- B.Perform a homogeneous migration directly from Oracle to Aurora.
- ✓ C.Use AWS Database Migration Service (DMS) with ongoing replication to keep the target in sync.
- ✓ D.Use AWS DMS data validation to compare source and target data.
- ✓ E.Use AWS Schema Conversion Tool (SCT) to convert the Oracle schema to PostgreSQL.
Why C: AWS DMS supports ongoing replication (change data capture) from Oracle to Aurora PostgreSQL, allowing the target database to stay synchronized with the source during the migration. This minimizes downtime by enabling a cutover after the initial load, rather than requiring a full outage for the entire migration.
Variation 3. A company is migrating an on-premises Oracle OLTP database to Amazon Aurora PostgreSQL. The database has a complex schema with stored procedures, triggers, and sequences. During the migration, the team notices that the conversion tool reports several incompatibilities. Which strategy should the team use to handle the database schema changes with minimal downtime?
medium- A.Deploy Amazon RDS for PostgreSQL with Babelfish to run Oracle PL/SQL code natively.
- ✓ B.Use AWS Database Migration Service (DMS) with the AWS Schema Conversion Tool (SCT) to convert the schema and migrate data, then handle remaining incompatibilities during a cutover window.
- C.Use pg_dump and pg_restore to migrate the schema, and then test and fix any errors.
- D.Manually rewrite all stored procedures and triggers to PostgreSQL syntax before migration.
Why B: AWS DMS with SCT is the recommended approach for heterogeneous migrations like Oracle to Aurora PostgreSQL. SCT converts the schema (including stored procedures, triggers, and sequences) and identifies incompatibilities, while DMS handles ongoing replication to minimize downtime. The remaining incompatibilities can be resolved during a planned cutover window, which is the standard strategy for complex schema migrations with minimal downtime.
Variation 4. A company is migrating an on-premises Oracle database to Amazon Aurora PostgreSQL. The database is used for a financial application that requires complex joins and transactions. Which migration strategy is MOST appropriate?
medium- A.Use AWS DMS with native Oracle to PostgreSQL endpoint
- B.Use Oracle GoldenGate to replicate data to Aurora PostgreSQL
- ✓ C.Use AWS SCT to convert the schema and AWS DMS to migrate data
- D.Use pg_dump to export the Oracle database and restore to Aurora PostgreSQL
Why C: AWS Schema Conversion Tool (SCT) is required to convert the Oracle schema (including complex joins and transaction logic) to a PostgreSQL-compatible format, and AWS Database Migration Service (DMS) performs the ongoing data migration with minimal downtime. This combination handles both schema transformation and data replication for heterogeneous migrations, which is essential for a financial application with complex joins and transactions.
JA
Written by Johnson Ajibi, MSc IT Security
Senior Network & Security Engineer · founder of Courseiva
This DBS-C01 practice question is part of Courseiva's free Amazon Web Services certification practice question bank. Courseiva provides original exam-style practice questions with explanations, topic-based practice, mock exams, readiness tracking, and study analytics to help learners prepare for the DBS-C01 exam.