GS_SEG_SEGMENTS

GS_SEG_SEGMENTS displays information about segments in all tablespaces, including tables, indexes, TOAST, TOAST INDEX segments, and fsm fork and vm fork segments. Only an administrator can query the information.

**Table 1** GS_SEG_SEGMENTS columns
Name	Type	Description
node_name	text	Node name.
schema_name	name	Namespace to which a segment belongs.
segment_name	name	Segment name. Source: pg_class and pg_partition.relname.
partition_name	name	Partition name of the segment object; NULL if the segment object is not partitioned. Source: pg_partition.relname.
forknum	integer	Fork type of a segment object. Value range: 0: main fork. 1: fsm fork. 2: vm fork.
segment_type	text	Segment object type. Value range: table: segment-page ordinary table. table partition: segment-page partitioned table (main table and child table) and segment-page level-2 partitioned table (level-1 partitioned table). table subpartition: segment-page level-2 partitioned table (top node table and level-2 partitioned table). index: index of a segment-page ordinary table. index partition: index of a segment-page partitioned table or level-2 partitioned table. global partition index: global index for segment-page partitioned tables and level-2 partitioned tables. toast: segment-page TOAST table. toast index: index of a segment-page TOAST table.
tablespace_name	name	Tablespace to which a segment belongs.
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.
head_block_id	bigint	Page number of the segment header.
contents	text	Storage content of a data file. Value range: permanent: permanent. unlogged: no log. temporary: global temporary. temporary2: local temporary.
table_name	name	Name of the base table to which a segment belongs.
blocks	bigint	Number of logical pages of a segment.
total_blocks	bigint	Number of physical pages of a segment.
extents	integer	Number of logical extents of a segment.
total_extents	integer	Number of physical extents of a segment.
head_lsn	text	Segment header LSN.
level0_slots	bigint[]	Level-0 slot array of segment extent mapping.
level1_slots	bigint[]	Level-1 slot array of segment extent mapping.
fork_head	bigint[]	Fork head array of a segment.