47.53. pgxc_class

Note: XCONLY: The following description applies only to Postgres-XC.

The catalog pgxc_class stores information whether each table is replicated or distributed, as well as distribution method and the distribution column.

Table 47-54. pgxc_class Columns

NameTypeReferencesDescription
pcrelidoidpg_class.oidOID of the table
pclocatortypechar  Type of locator.
pcattnumint2  Column number of used as distribution key.
pchashalgorithmint2  Indicates hashing algorithm used to distribute the tuples.
pchashbucketsint2  Indicates the number of hash buckets used to distribute duple.
nodeoidsoidvectorpgxc_node.oid List of node OIDs where table is located. This list is ordered by pgxc_node.node_name. This list is then indexed in information in user session cache and reused as a node target list when doing SQL operations on cluster tables.