The format is proprietary and there is no public official document which would describe the structure. Here is a brief summary of various sources which are publicly available. One might think that there is very little information available, but that’s not true.
This is a list I have made in the past when I was making some research for myself. If I have missed something interesting – please let me know.
Open source projects
Code is written in C, license is LGPL, supported very poorly format from Oracle version 10, last update was in 11th March 2008.
2. OracleRedoParser – written by zhihuiFan / 樊智辉, source code on github.
License of code is unknown. Quote: This is an internal/dead project and we do not support it anymore. Put it here just in case it may helpful for any people. Last update 27.05.2015. Code written in C and C++. Partial support of basic opcodes.
Project written in C++, allowing to read redo logs (database version 11.2+) and writes transactions to Kafka, licensed on GPL v.3. Please refer to documentation for details.
1. Graham Thornton, Disassembling the Oracle Redo Log, PDF, 2000
2. Paul M. Wright, Oracle Database Forensics using LogMiner, PDF, 2005
3. Julian Dyke, Redo Internals, PPT, 2005
4. Julian Dyke, Transaction Internals, PPT, 2007
5. David Litchfield, Oracle Forensics Part 1: Dissecting the Redo Logs, PDF, 2007
6. David Litchfield, Oracle Forensics Part 2: Locating-Dropped-Objects, PDF, 2007
7. Riyaj Shamsudeen, Debunking the myths about redo, undo, commit & rollback, PDF, 2008,
8. Riyaj Shamsudeen, Redo internals and tuning by redo reduction, PDF, 2008
9. Vit Špinka, Life of a Transaction, PDF, 2014
10. Vit Špinka, Evolution of Oracle Redo Logs Through Versions, PDF, 2014
11. Vit Špinka, Internals of the Oracle Database 12cMultitenant Architecture, PDF, 2014
12. Vit Špinka, What a DBA Should Know or How to Know Your Way Around Database, PDF, DOAG, 2015
13. Jure Kajzer, Forensic analysis ofOracle log files, PDF, SIOUG, 2014
5. Stefano Sorbara’s blog in Italian, including: Analisi forense su Oracle – analisi esadecimale dei Redo Logs,
6. Ask Maclean, with Redo opcode reference,
7. Adam Leszczyński’s blog with this page with as a summary 🙂