The gp_segment_configuration table contains information about mirroring and segment instance configuration.

Table 1. pg_catalog.gp_segment_configuration
column type references description
dbid smallint   Unique identifier of a segment (or master) instance.

For a segment the value is from 0 to N-1, where N is the number of primary segments in the system.

For the master, the value is always -1.

mode char   The synchronization status of a segment instance with its mirror copy. Values are s (synchronized) or n (not synchronized).
Note: This column always shows n for the master segment and s for the standby master segment, but these values do not describe the synchronization state for the master segment. Use gp_stat_replication to determine the synchronization state between the master and standby master.
status char   The fault status of a segment instance. Values are u (up) or d (down).
hostname text   The hostname of a segment host.
address text   The hostname used to access a particular segment instance on a segment host. This value may be the same as hostname on systems that do not have per-interface hostnames configured.
datadir text   Segment instance data directory.