Trails are used in Oracle GoldenGate to support the continuous extraction and replication of database changes.
A trail can exist on the source or target system, or on an intermediary system.
Only one primary Extract process writes to a trail.
Processes that read the trail include:
- Path (MA only)
- Data Pump Extract (CA only)
Add a local or remote trail with GGSCI (CA) command:
GGSCI > Add Exttrail | Rmttrail <trail_name>, Extract <group_name>, Megabytes <n>
If you are using a data pump Extract:
* The primary Extract needs a local tail (ExtTrail)
* The data pump Extract needs a remote trail (RmtTrail)
GGSCI > Add Exttrail /u01/ogg/dirdat/aa, Extract Finance, Megabytes 10
GGSCI > Add Rmttrail /u01/ogg/dirdat/bb, Extract parts, Megabytes 10
Start an Extract process with the adminclient (MA) command:
OGG > Start Extract <group_name>
OGG > Info Extract <group_name>
If the output trail is remote, this normally triggers the target Manager process to start a Server Collector process with the default parameters.