GP 6 overall architecture study notes

• Master, Secondary, Segment, Mirror are all pg instances
• Note that the pg used by gp has some customization
• Data replication between instances is implemented through the WAL log mode
• Mirrors and segments of the same data should be staggered to avoid being on the same physical machine
• Large-scale data import and export are recommended through external tables instead of copy mode (Greenplum Administrator Guide 6.2.1.pdf) mentioned that copy will pass through master
• Secondary should be deployed separately by default and without any other tasks to ensure fast switchover in the event of a problem with the master