Oracle LogMiner Agent

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Introduction

The Oracle LogMiner agent provides Change Data Capture (CDC) capabilities using Oracle’s native LogMiner utility. This approach enables capturing changes from Oracle’s redo logs (both online and archived) to replicate data in real-time.

Key Features

  • Native integration with Oracle’s transaction logs via the LogMiner utility

  • Real-time change data capture from both online and archived redo logs

  • Minimal impact on source database performance

  • Built-in JDBC driver connection

  • ArenaCache for committed changes (one file per entity as of 2.2.11.2) — the same source cache now used by other cache-enabled agents

  • Off-heap, per-transaction spill store for large or long-running uncommitted transactions — keeping the JVM heap pressure low regardless of transaction size

  • Automatic in-place recovery on Oracle host restarts or network outages — reconnects from the persisted SCN checkpoint without requiring a software restart

  • Configurable socket read timeout to bound recovery time when Oracle becomes unreachable

Supported Versions

The Oracle LogMiner agent requires:

  • Oracle Database version 11.2.0.4 (11.2g) or higher

  • Oracle Database Standard or Enterprise edition

  • Oracle RAC is also supported in this agent.

Connecting

Gluesync connects to Oracle using a standard JDBC connection. You can configure the agent in two ways:

Custom connection string

Within the agent configuration wizard, open the //Advanced// section and paste your custom JDBC string. Start from the TNS entry you already manage and build a full connection string similar to:

jdbc:oracle:thin:@(DESCRIPTION=(ADDRESS=(PROTOCOL=TCP)(HOST=your_host)(PORT=1521))(CONNECT_DATA=(SERVICE_NAME=your_service_name)))

Use this option whenever you must reuse an existing tnsnames.ora definition or need advanced Oracle descriptors.

Connection via SCAN (Single Client Access Name)

Alternatively, you can connect through Oracle SCAN.

Platform supported features

Feature Support Notes

Target role

✅

Writes to Oracle via the built-in JDBC driver.

Source role

✅

Captures transaction log changes through native LogMiner.

Snapshots

✅

Supports snapshot tasks before CDC to seed target systems.

CDC

✅

Real-time CDC using LogMiner.

CDC type

Oracle LogMiner (transaction logs)

See Oracle LogMiner documentation.

User defined data types

✅

Supports user defined data types.

Bulk load

✅

Supports bulk loading both for CDC and snapshot operations.

Database pooling

✅

Supports connection pooling for efficient resource utilization across multiple pipelines.

Source committed-change buffer (ArenaCache)

✅

Committed changes are persisted in ArenaCache (one file per entity as of 2.2.11.2) before being forwarded. ArenaCache was first proven on this agent and is now the platform source cache. See Source-side cache.

Source in-flight transaction spill

✅

Uncommitted transactions are spilled to an off-heap, memory-mapped file (one file per XID). The JVM heap is not impacted by large or long-running transactions. Files are deleted atomically on COMMIT or ROLLBACK.

Target persisted internal cache

N/A

Writes flow directly through JDBC; no extra caching.

Driver / connector

Built-in JDBC driver

Requires standard Oracle JDBC driver.

Chains

N/A

Not yet supported.

Truncate operation support (reading)

✅

CDC stream detects TRUNCATE operations from redo logs.

Truncate operation support (writing)

✅

Supports Core Hub “TRUNCATE before snapshot” option.

Setup Options

Choose your setup guide based on your Oracle database infrastructure:

Additional Resources