gp_segment_configuration

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

This table is populated only on the master. This table is defined in the pg_global tablespace, meaning it is globally shared across all databases in the system.

Column Type Description

Column	Type	Description
dbid	smallint	Unique identifier of a segment (or master) instance
content	smallint	The content identifier for a segment instance. A primary segment instance and its corresponding mirror will always have the same content identifier. For a segment the value is from `0` to `N-1`, where `N` is the number of primary segments in a cluster. For the master, the value is always `-1`
role	char	The role that a segment is currently running as. Values are `p` (primary) or `m` (mirror)
preferred_role	char	The role that a segment was originally assigned at initialization time. Values are `p` (primary) or `m` (mirror)
mode	char	The synchronization status of a segment instance with its mirror copy. Values are `s` (synchronized) or `n` (not in sync). 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)
port	integer	The TCP port the database server listener process is using
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

dbid

smallint

Unique identifier of a segment (or master) instance

content

smallint

The content identifier for a segment instance. A primary segment instance and its corresponding mirror will always have the same content identifier.

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

For the master, the value is always -1

role

char

The role that a segment is currently running as. Values are p (primary) or m (mirror)

preferred_role

char

The role that a segment was originally assigned at initialization time. Values are p (primary) or m (mirror)

mode

char

The synchronization status of a segment instance with its mirror copy. Values are s (synchronized) or n (not in sync).

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)

port

integer

The TCP port the database server listener process is using

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

gp_id

gp_version_at_initdb