PGXC_NODE

The PGXC_NODE system catalog stores information about database instance nodes. In the centralized system, only the definition of this table can be queried.

**Table 1** PGXC_NODE columns
Name	Type	Description
oid	oid	Row identifier (hidden attribute, which must be specified).
node_name	name	Node name.
node_type	"char"	Node type. C: CN D: DN S: standby node
node_port	integer	Port number of the node.
node_host	name	Host name or IP address of a node. (If a virtual IP address is configured, its value is a virtual IP address.)
node_port1	integer	Port number of a replication node.
node_host1	name	Host name or IP address of a replication node. (If a virtual IP address is configured, its value is a virtual IP address.)
hostis_primary	Boolean	Specifies whether a primary/standby switchover occurs on the current node. t (true): yes f (false): no
nodeis_primary	Boolean	Specifies whether the current node is preferred to execute non-query operations in the replication table. t (true): yes f (false): no
nodeis_preferred	Boolean	Specifies whether the current node is preferred to execute queries in the replication table. t (true): yes f (false): no
node_id	integer	Node identifier. The value is obtain by calculating the value of node_name using the hash function.
sctp_port	integer	Port used by the TCP proxy communications library of the primary node to listen to the data channel. (The SCTP communications library is no longer supported in the current version.)
control_port	integer	Port used by the TCP proxy communications library of the primary node to listen to the control channel.
sctp_port1	integer	Port used by the TCP proxy communications library of the standby node to listen to the data channel. (The SCTP communications library is no longer supported in the current version.)
control_port1	integer	Port used by the TCP proxy communications library of the standby node to listen to the control channel.
nodeis_central	Boolean	Specifies whether the current node is a CN. It is invalid for DNs. t (true): yes f (false): no
nodeis_active	Boolean	Specifies whether the current node is normal. It is invalid for DNs. t (true): yes f (false): no