Oracle GOLDEN GATE Concept & Architecture

Oracle Golden Gate is a tool provided by oracle for transactional data replication among oracle databases and other RDBMS tools like Oracle, DB2, SQL Server, Ingres, MySQL etc.

What we can achieve with this tool:

• High Availability
• Data Integration
• Zero downtime upgrade and migration
• Live reporting database
• Clone Database

Oracle Golden Gate Architecture

Oracle Golden Gate server runs on both source and target server. Oracle Golden Gate is installed as an external component to the database and it won’t uses database resource, in turn it won’t affect database performance.

Golden gate Architecture

MANAGER

 The Manager process runs on both source and target systems and it is the heart or control process of Oracle Golden Gate. Manager must be up and running before you create EXTRACT or REPLICAT process. Manager performs Monitoring, restarting oracle golden gate process, report errors, report events, maintains trail files and logs etc.

EXTRACT:

Extract runs on the source system and it is the extraction mechanism for oracle Golden Gate (capture the changes which happens at the source database).

Extract process captures all the changes that are made to objects that are configured for synchronization.  Multiple Extract processes can operate on different objects at the same time. For example once process could continuously extract transactional data changes and stream those to a decision support database. while another process performs batch extracts for periodic reporting or, two extract processes could extract and transmit in parallel to two replicate processes ( with two trails) to minimize target latency when the databases are large.

DATAPUMP

 Data pump is the secondary extract process with in source oracle Golden Gate configuration. You can have the source oracle Golden Gate configured without Data pump process also, but in this case Extract process has to send the data to trail file at the target. If the Data pump is configured the primary extract process writes the data to the source trail file and Data pump will read this trail file and propagate the data over the network to target trail file.

REPLICAT

 Replicate process runs on the target system. Replicate reads extracted transactional data changes and DDL changes (IF CONFIGURED) that are specified in the Replicate configuration, and then it replicates them to the target database.

 TRAILS OR EXTRACTS

 To support the continuous extraction and replication of source database changes, Oracle Golden Gate stores the captured changes temporarily on the disk in a series of files call a TRAIL. A trail can exist on the source or target system and even it can be in an intermediate system, depending on how the configuration is done. On the local system it is known as an EXTRACT TRAIL and on the remote system it is known as REMOTE TRAIL.

COLLECTOR

 Collector is a process that runs in the background on the target system. Collector receives extracted database changes that are sent across the TCP/IP network and it writes them to a trail or extract file.

(source: Oracle Golden Gate Administration Guide)