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Updated on 2024-05-07 GMT+08:00
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PGXC_NODE

PGXC_NODE records information about cluster nodes.

  • PGXC_NODE stores information about database instance nodes. The PGXC_NODE system catalog has specific meanings only on CNs and its data is valid and correct.
  • In the result of querying the PGXC_NODE system catalog on a DN, only the node_id column is meaningful. Other columns are meaningless and invalid.
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 DN.

node_port

integer

Port ID 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 communication library of the primary node to listen to the data channel. (The SCTP communication 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 communication library of the standby node to listen to the data channel. (The SCTP communication 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 central control node. It is used only for CNs and is invalid for DNs.

  • t (true): yes
  • f (false): no

nodeis_active

Boolean

Specifies whether the current node is normal. It is used to mark whether the CN is removed and is invalid for DNs.

  • t (true): yes
  • f (false): no
Parent topic: System Catalogs