Help Center/ GaussDB/ Developer Guide(Distributed_V2.0-8.x)/ System Catalogs and System Views/ System Views/ Segment-Page Storage/ GS_SEG_SPC_SEGMENTS
Updated on 2025-08-19 GMT+08:00
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GS_SEG_SPC_SEGMENTS

GS_SEG_SPC_SEGMENTS displays information about used segments in all tablespaces. Only an administrator can query the information.

Table 1 GS_SEG_SPC_SEGMENTS columns

Name

Type

Description

node_name

text

Node name.

tablespace_name

name

Tablespace name.

file_id

integer

Data file ID. Value range: an int4 value in the range [1,5].

bucketnode

integer
  • 0 to 1023 indicate the bucket nodes of a hash bucket table.
  • 1024 indicates the bucket node of a segment-page ordinary table.
  • 1025 indicates the bucket node of a segment-page global temporary table.
  • 1026 indicates the bucket node of a segment-page unlogged table.
  • 1027 indicates the bucket node of a segment-page local temporary table.
  • 2048 to 6143 indicate the bucket nodes of a range bucket table.

forknum

integer

Fork type of a segment object. Value range:

  • 0: main fork.
  • 1: FSM fork.
  • 2: VM fork.

block_id

bigint

Start page number of a data extent.

blocks

integer

Data extent size. The value can be 1, 8, 128, 1024, or 4096.

contents

text
Storage content of a data file. Value range:
  • permanent: permanent.
  • unlogged: no log.
  • temporary: global temporary.
  • temporary2: local temporary.

in_used

text

Specifies whether a resource has been allocated. The value can be Y or N.

mapblock_location

text

Position of the extension in the map block. The format is (page_id, offset).

head_file_id

integer

Segment header file ID.

head_block_id

bigint

Page number of the segment header.

usage_type

text
Extended usage type. The options are as follows:
  • segment head: segment header.
  • fork head: fork header.
  • level1 page: level-1 page.
  • data extent: data extents.

remain_flag

text

Specifies whether it is a residual extent after the SHRINK operation. The value can be Y or N.

special_data

integer

Special data section of the reverse pointer corresponding to an extent.

ipblock_location

text

Position of the extended reverse pointer. The format is (block_id, offset).
Parent topic: Segment-Page Storage