Oracle OpenLogReplicator Agent
Introduction
The Oracle OpenLogReplicator agent provides Change Data Capture by reading transactions directly from the database redo log files.
Key Features
-
Requires no specific configuration of the source database, just archive log files access;
-
Minimal setup requirements
How It Works
With the Oracle OpenLogReplicator agent, transactions are directly decoded from redo log files, therefore it is crucial that the process has physical access to files and the files aren’t deleted before they’re processed. To provide this functionality the agent supports the following ways to access log files:
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Mounting Volumes (preferred and easier method);
-
SSHFS;
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NFS;
| Currently the OpenLogReplicator agent only supports uppercase database objects. |
Technology under the hood
The Oracle OpenLogReplicator is written in C++ and it uses client libraries to connect to the database. All changes in the database, results of DML commands like INSERT, UPDATE, DELETE are written to database redo logs. These files contain information about what has been changed. The Oracle OpenLogReplicator parses these files and streams the contect to the agent through network. To simplify this process the instance of the Oracle OpenLogReplicator is controlled by our agent and it is stored in the same docker container this guarantee full managability without any additional configuration and enhanced security as archive log data does not leave the container and cannot be introspected.
Supported Versions
The Oracle OpenLogReplicator agent supports the following databases:
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Oracle databases: 11.2g, 12.1g, 12.2g, 18c, 19c, 21c, 23ai.
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Oracle databases editions: XE/DE, SE, SE2, PE, EE.
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Supported database block sizes: 2k, 4k, 8k, 16k, 32k.
NOTE: Please note that OLR does not currently support Oracle RAC.
Platform supported features
| Feature | Support | Notes |
|---|---|---|
Target role |
✅ |
Writes to Oracle via the bundled JDBC driver (all editions). |
Source role |
✅ |
Captures redo/archived log changes through OpenLogReplicator (OLR). |
Snapshots |
✅ |
Supports running snapshots before CDC to seed downstream systems. |
CDC |
✅ |
Real-time CDC driven by OLR parsing redo logs. |
CDC type |
Redo log mining (OpenLogReplicator) |
Requires access to archived/redo logs; RAC not supported. |
Bulk load |
✅ |
Integrates with staging-table Bulk load workflows for high-volume mirroring. |
Source persisted internal cache |
✅ |
Agent stores local offsets/state for processed redo segments. |
Target persisted internal cache |
N/A |
Writes persist directly to Oracle via JDBC. |
Driver / connector |
Built-in JDBC driver + OLR process |
OLR runs alongside the agent container; data never leaves the environment. |
Chains |
N/A |
Not yet supported. |
Truncate operation support (reading) |
✅ |
Redo log mining detects TRUNCATE statements and forwards them. |
Truncate operation support (writing) |
✅ |
Supports Core Hub “TRUNCATE before snapshot” when targeting Oracle. |