SCN Recovery & LogMiner Gap Diagnosis
Simulate Oracle log retention failures, diagnose SCN gaps, and follow recovery playbooks for Debezium on Kubernetes. Covers incremental snapshots, JDBC offset manipulation, and schema history reconstruction.
What is Oracle CDC?
Oracle CDC is how you get a continuous stream of changes out of an Oracle database and into the rest of your stack. Every insert, update, and delete that gets committed is captured and delivered downstream in near real time - without polling, without triggers, and without touching your application. It's the foundation for real-time analytics feeds, data lake ingestion, microservice event sync, and zero-downtime database migrations.
Oracle gives you several ways to read change data, and they're quite different in cost, latency, and complexity. The right one depends on what license tier you're on, how much latency you can accept, and where the events need to land - a Kafka topic, an Iceberg table, or another database.
Log-based CDC reads Oracle's redo logs directly - the same journal Oracle uses for crash recovery. That means every committed change is captured in order, including hard deletes, with no table scans and no extra load on the primary database. Polling-based approaches miss deletes and put repeated query load on the source; log-based CDC avoids both.
Oracle CDC Methods Compared
| Method | License | Latency | Best for |
|---|---|---|---|
| LogMiner via Debezium |
Included | Seconds | Open-source CDC, Kafka & HTTP pipelines, cost-sensitive deployments |
| XStream via Debezium |
GoldenGate | Sub-second | Low-latency CDC where GoldenGate license already exists |
| Oracle GoldenGate | GoldenGate | Sub-second | Enterprise replication, zero-downtime migrations, heterogeneous targets |
| Triggers | Included | Synchronous | Simple auditing on low-volume tables; not recommended for high-throughput CDC |
Guides & Interactive Tools
Hands-on tools and research papers covering Oracle CDC in production.
LogMiner Performance Tuning
Generate optimised Debezium configurations for Oracle LogMiner. Compare throughput, latency, CPU, and memory profiles with an interactive radar chart and get a ready-to-use application.properties output.
XStream Configuration Explorer
Dashboard covering the full Oracle XStream pipeline: connection pooling lifecycle, JDBC offset and schema history storage, RegexRouter SMT simulation, CloudEvents format, and HTTP sink configuration.
Concurrency & Scaling Analysis
Deep dive into running multiple Debezium Oracle connectors simultaneously. Compares XStream vs LogMiner constraints for same-schema and multi-schema deployments, with Kubernetes HA patterns.
Oracle Archive Log Management
Interactive guide to configuring archive log retention for Debezium LogMiner. Covers the RMAN conflict, dual-destination strategy, and SCN-aware cleanup to prevent missing log errors.
LogMiner JDBC Config Generator
Generate production-ready Debezium Server config with JDBC-backed offset and schema history storage. Covers profiles, snapshot modes, CDB/PDB topology, and validation steps.
Oracle CDC Methods Deep Dive - coming soon
Detailed technical comparison of LogMiner, XStream, GoldenGate, triggers, and Oracle Advanced Queuing as CDC mechanisms.
Oracle DDL Mining Strategy
Compare redo_log_catalog and online_catalog strategies for managing DDL changes with Debezium. Step-by-step playbooks for safe schema evolution with no data loss.
Oracle EBR CDC Analysis
Feasibility analysis for Debezium LogMiner CDC in Edition-Based Redefinition environments. Covers redo_log_catalog strategy, concurrent edition constraints, and DDL parsing.
LogMiner Performance Tuning
Interactive risk analyzer and tuning guide for Debezium Oracle LogMiner throughput: redo log sizing, logminer_unbuffered mode, and Kafka producer settings.
Oracle Redo Log Sizing
Architecture flow, performance simulation, and SCN recovery guide for sizing Oracle redo logs to support stable Debezium LogMiner CDC pipelines.
Oracle CDC: EBR and Online DDL Compatibility
Compare GoldenGate, XStream, and Debezium on EBR cutover handling, supplemental logging, online DDL locking, and configuration recommendations for Oracle 19c and 23ai.
Frequently Asked Questions
Oracle CDC can be implemented via LogMiner (built-in API, no extra license), XStream (dedicated streaming API, requires GoldenGate license), Oracle GoldenGate (enterprise replication product), or database triggers (simple but adds synchronous write overhead). LogMiner via Debezium is the most widely-used open-source approach.
LogMiner is included with all Oracle Database editions at no additional cost. XStream requires the Oracle GoldenGate license. Oracle GoldenGate itself is a separate, enterprise-priced product. Trigger-based CDC requires no extra license but creates synchronous overhead on every DML operation.
LogMiner is built into Oracle Database - no extra license, no extra software. It reads the redo and archive logs and surfaces committed DML changes as SQL-queryable rows. Debezium uses the LogMiner API to detect those changes and stream them to downstream systems.
Oracle XStream is a streaming API that delivers change records from an Outbound Server process to client applications. It provides lower latency than LogMiner and a more structured API, but requires an Oracle GoldenGate license. Debezium supports XStream as an alternative to LogMiner for Oracle CDC.
Yes. Debezium's Oracle connector uses LogMiner by default, which requires no GoldenGate license. This is the most widely-deployed open-source Oracle CDC approach. GoldenGate is only required if you use XStream mode or the GoldenGate product itself.