Free Online Book

The Migration You Don't Have to Redo

A production-grade guide to Oracle → PostgreSQL migration — from source discovery to cutover and beyond. 20 chapters, 3 appendices, built from real incidents.

Contents

Part IChapters 1–4

Understanding the Source

Why this is not a schema translation problem. How to read a source system before touching it. The empty-string trap. Data type precision and semantic loss.

Part IIChapters 5–8

Schema & Object Migration

Identifier case normalization and the quoted-identifier trap. Constraints, indexes, DDL ordering. Sequences and identity drift. PL/SQL to PL/pgSQL.

Part IIIChapters 9–12

Data Movement

Full load design: SCN anchoring, chunked cursors, LOB streaming, restart/checkpoint. CDC: LogMiner vs Debezium, lag tracking. Staging as an audit ledger. Dependency resolution.

Part IVChapters 13–14

Safety & Performance

Chunk atomicity, savepoints, compensating writes, rollback design. COPY protocol, WAL tuning, parallel workers, backpressure.

Part VChapters 15–17

Validation

Reconciliation modes: count, hash, sample, aggregate. Reading and classifying discrepancies. Reconciliation as a feedback loop that improves the product.

Part VIChapters 18–20

Operations & Cutover

Observability, dashboard, runbook integration. Go/no-go procedure, the 20-minute switch, rollback decision tree. Building the migration team.

All Chapters

  1. PrefacePreface
  2. Chapter 1Why Transform Pulsride Exists
  3. Chapter 2Reading the Source System
  4. Chapter 3The Empty String Trap
  5. Chapter 4Data Type Mapping That Breaks in Production
  6. Chapter 5Names, Quoting, and Case Sensitivity
  7. Chapter 6Constraints, Indexes, and DDL Migration
  8. Chapter 7Sequences, Identity, and Key Generation
  9. Chapter 8PL/SQL to PL/pgSQL
  10. Chapter 9Full Load Before CDC
  11. Chapter 10CDC Design for Migration
  12. Chapter 11Staging as Product Memory
  13. Chapter 12Dependency Resolution at Runtime
  14. Chapter 13Transactional Safety and Rollback
  15. Chapter 14Performance and Parallelism
  16. Chapter 15Reconciliation-Driven Validation
  17. Chapter 16Making Sense of Reconciliation Outputs
  18. Chapter 17How Reconciliation Improves the Product
  19. Chapter 18Observability and Operator Workflow
  20. Chapter 19Cutover Readiness and the Final Switch
  21. Chapter 20Building the Product Team
  22. Appendix AEdge-Case Playbook
  23. Appendix BPractical Labs
  24. Appendix COperational Checklists