PGXC_NODE

The PGXC_NODE system catalog stores information about database instance nodes. This system catalog has specific meanings only in distributed scenarios. Centralized systems can query only the table definition.

**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	Whether a primary/standby switchover occurs on the current node t (true): yes f (false): no
nodeis_primary	boolean	Whether the current node is preferred to execute non-query operations in the replication table t (true): yes f (false): no
nodeis_preferred	boolean	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 communication library or SCTP communication library of the primary node to listen on the data channel. (Due to specification changes, the current version no longer supports the current feature. Do not use this feature.)
control_port	integer	Port used by the TCP proxy communications library of the primary node to listen on the control channel
sctp_port1	integer	Port used by the TCP proxy communication library or SCTP communication library (Due to specification changes, the current version no longer supports the current feature. Do not use this feature.) of the standby node to listen on the data channel
control_port1	integer	Port used by the TCP proxy communications library of the standby node to listen on the control channel
nodeis_central	boolean	Whether the current node is a CN. It is invalid for DNs. t (true): yes f (false): no
nodeis_active	boolean	Whether the current node is normal. It is invalid for DNs. t (true): yes f (false): no