Migrating VLDBs from Oracle to Azure Database for PostgreSQL (Flexible Server) | POSETTE 2026

Adithya Kumaranchath presents his POSETTE 2026 talk on migrating very large databases (VLDBs) from Oracle to Azure Database for PostgreSQL – Flexible Server, focusing on predictable performance and near-zero-downtime cutovers.

Overview

The session walks through a practical, end-to-end migration approach for multi-terabyte Oracle workloads moving to a managed PostgreSQL service on Azure.

Migration lifecycle covered

• Validating schema compatibility before moving data
• Planning write-ahead log (WAL) throughput to support migration and replication
• Designing storage layout appropriate for large-scale workloads
• Optimizing network throughput and bulk-load operations
• Using logical replication to enable near-zero-downtime cutovers

Advanced VLDB considerations

• Handling partitions at scale
• Managing large objects (LOBs)
• Dealing with long-running transactions during migration and cutover

Common pitfalls and optimization strategies

The talk highlights issues that frequently appear in VLDB migrations and how to avoid them:

• Table and index bloat
• Autovacuum stalls
• Slow COPY performance
• Resource throttling caused by misaligned compute sizing or IOPS configuration

Real-world guidance

• Customer examples of Oracle-to-PostgreSQL migrations
• A repeatable VLDB migration checklist
• Tuning templates intended to be usable immediately

Related links

• POSETTE conference site: https://posetteconf.com
• POSETTE talks playlist: https://aka.ms/posette-playlist