Overview

Oracle Golden Gate servers are replication tool for Oracle and can be used to provide DR and HA as follows:

Unidirectional Replication

Bidirectional

One to Many

Round replication

As such there are a lot of methods and ways to monitor

General

General Troubleshooting

Extract Redo log file via Log Miner

Extract binary (long raw) column

Specific

OGG01168 - Encountered an update for target table with no unique key