Postgres-XC 1.2 Documentation | ||||
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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
Name | Type | References | Description |
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pcrelid | oid | pg_class.oid | OID of the table |
pclocatortype | char | Type of locator. | |
pcattnum | int2 | Column number of used as distribution key. | |
pchashalgorithm | int2 | Indicates hashing algorithm used to distribute the tuples. | |
pchashbuckets | int2 | Indicates the number of hash buckets used to distribute duple. | |
nodeoids | oidvector | pgxc_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. |