Updated on 2023-10-23 GMT+08:00

PGXC_SLICE

PGXC_SLICE is a system catalog created for recording range distribution and list distribution details. Currently, range interval cannot be used to automatically scale out shards. It is reserved in the system catalog.

This system catalog has specific meanings only in distributed scenarios. Centralized systems can query only the table definition.

Table 1 PGXC_SLICE columns

Name

Type

Description

relname

name

Table name or shard name, which is distinguished by type.

type

"char"

When the value is t, relname indicates the table name. When the value is s, relname indicates the shard name.

strategy

"char"

r: range distribution table

l: list distribution table

This value will be extended for subsequent interval shards.

relid

oid

OID of the distribution table to which the tuple belongs.

referenceoid

oid

OID of the referenced distribution table, which is used for slice reference table creation syntax.

sindex

integer

Position of the current boundary in a shard when the table is a list distribution table.

interval

text[]

Reserved column

transitboundary

text[]

Reserved column

transitno

integer

Reserved column

nodeoid

oid

When relname is set to a shard name, nodeoid indicates the OID of the DN where the shard data is stored.

boundaries

text[]

When relname is set to a shard name, this parameter indicates the boundary value of the shard.

specified

boolean

Whether the DN corresponding to the current segment is explicitly specified in the DDL.

sliceorder

integer

User-defined shard sequence.