Help Center/ GaussDB/ Developer Guide(Distributed_V2.0-8.x)/ SQL Reference/ Functions and Operators/ Internal Functions

Updated on 2025-05-29 GMT+08:00

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Internal Functions

The following functions of GaussDB use internal data types, which cannot be directly called by users.

Selectivity calculation functions

areajoinsel	areasel	arraycontjoinsel	arraycontsel	contjoinsel	contsel	eqjoinsel
eqsel	iclikejoinsel	iclikesel	icnlikejoinsel	icnlikesel	icregexeqjoinsel	icregexeqsel
icregexnejoinsel	icregexnesel	likejoinsel	likesel	neqjoinsel	neqsel	nlikejoinsel
nlikesel	positionjoinsel	positionsel	regexeqjoinsel	regexeqsel	regexnejoinsel	regexnesel
scalargtjoinsel	scalargtsel	scalarltjoinsel	scalarltsel	tsmatchjoinsel	tsmatchsel	-

Statistics collection functions

array_typanalyze	range_typanalyze	ts_typanalyze
local_rto_stat	remote_rto_stat	gs_plan_trace_delete
gs_plan_trace_watch_sqlid	gs_plan_trace_show_sqlids	standby_statement_history_internal

Internal functions for sorting

bpchar_sortsupport

bytea_sortsupport

date_sortsupport

numeric_sortsupport

timestamp_sortsupport

Internal type processing functions

abstimerecv	euc_jis_2004_to_utf8	int2recv	line_recv	oidvectorrecv_extend	tidrecv	utf8_to_koi8u
anyarray_recv	euc_jp_to_mic	int2vectorrecv	lseg_recv	path_recv	time_recv	utf8_to_shift_jis_2004
array_recv	euc_jp_to_sjis	int4recv	macaddr_recv	pg_node_tree_recv	time_transform	utf8_to_sjis
ascii_to_mic	euc_jp_to_utf8	int8recv	mic_to_ascii	point_recv	timestamp_recv	utf8_to_uhc
ascii_to_utf8	euc_kr_to_mic	internal_out	mic_to_big5	poly_recv	timestamp_transform	utf8_to_win
big5_to_euc_tw	euc_kr_to_utf8	interval_recv	mic_to_euc_cn	pound_nexttoken	timestamptz_recv	uuid_recv
big5_to_mic	euc_tw_to_big5	interval_transform	mic_to_euc_jp	prsd_nexttoken	timetz_recv	varbit_recv
big5_to_utf8	euc_tw_to_mic	iso_to_koi8r	mic_to_euc_kr	range_recv	tintervalrecv	varbit_transform
bit_recv	euc_tw_to_utf8	iso_to_mic	mic_to_euc_tw	rawrecv	tsqueryrecv	varchar_transform
boolrecv	float4recv	iso_to_win1251	mic_to_iso	record_recv	tsvectorrecv	varcharrecv
box_recv	float8recv	iso_to_win866	mic_to_koi8r	regclassrecv	txid_snapshot_recv	void_recv
bpcharrecv	gb18030_to_utf8	iso8859_1_to_utf8	mic_to_latin1	regconfigrecv	uhc_to_utf8	win_to_utf8
btoidsortsupport	gbk_to_utf8	iso8859_to_utf8	mic_to_latin2	regdictionaryrecv	unknownrecv	win1250_to_latin2
bytearecv	-	johab_to_utf8	mic_to_latin3	regoperatorrecv	utf8_to_ascii	win1250_to_mic
byteawithoutorderwithequalcolrecv	gtsvector_compress	json_recv	mic_to_latin4	regoperrecv	utf8_to_big5	win1251_to_iso
cash_recv	gtsvector_consistent	koi8r_to_iso	mic_to_sjis	regprocedurerecv	utf8_to_euc_cn	win1251_to_koi8r
charrecv	gtsvector_decompress	koi8r_to_mic	mic_to_win1250	regprocrecv	utf8_to_euc_jis_2004	win1251_to_mic
cidr_recv	gtsvector_penalty	koi8r_to_utf8	mic_to_win1251	regtyperecv	utf8_to_euc_jp	win1251_to_win866
cidrecv	gtsvector_picksplit	koi8r_to_win1251	mic_to_win866	reltimerecv	utf8_to_euc_kr	win866_to_iso
circle_recv	gtsvector_same	koi8r_to_win866	namerecv	shift_jis_2004_to_euc_jis_2004	utf8_to_euc_tw	win866_to_koi8r
cstring_recv	gtsvector_union	koi8u_to_utf8	ngram_nexttoken	shift_jis_2004_to_utf8	utf8_to_gb18030	win866_to_mic
date_recv	hll_recv	latin1_to_mic	numeric_recv	sjis_to_euc_jp	utf8_to_gbk	win866_to_win1251
domain_recv	hll_trans_recv	latin2_to_mic	numeric_transform	sjis_to_mic	utf8_to_iso8859	xidrecv
euc_cn_to_mic	-	latin2_to_win1250	nvarchar2recv	sjis_to_utf8	utf8_to_iso8859_1	xidrecv4
euc_cn_to_utf8	inet_recv	latin3_to_mic	oidrecv	smalldatetime_recv	utf8_to_johab	xml_recv
euc_jis_2004_to_shift_jis_2004	int1recv	latin4_to_mic	oidvectorrecv	textrecv	utf8_to_koi8r	-
numeric_bool	int2vectorin_extend	int2vectorout_extend	int2vectorrecv_extend	int2vectorsend_extend	int8_accum	large_seq_rollback_ntree
large_seq_upgrade_ntree	int16eq	int16ge	int16gt	int16in	int16le	int16lt
int16mi	int16mul	int16ne	int16out	int16pl	int16recv	int16send
int16_bool	i16toi1	anyset_in	anyset_out	btint2setcmp	btint4setcmp	btint8setcmp
btsetcmp	btsetint2cmp	btsetint4cmp	btsetint8cmp	btsetsortsupport	float4	float8
hashsetint	hashsettext	int2	int2seteq	int2setge	int2setgt	int2setle
int2setlt	int2setne	int4	int4seteq	int4setge	int4setgt	int4setle
int4setlt	int4setne	int8	int8seteq	int8setge	int8setgt	int8setle
int8setlt	int8setne	set	set_in	set_out	set_recv	set_send
seteq	setge	setgt	setint2eq	setint2ge	setint2gt	setint2le
setint2lt	setint2ne	setint4eq	setint4ge	setint4gt	setint4le	setint4lt
setint4ne	setint8eq	setint8ge	setint8gt	setint8le	setint8lt	setint8ne
setle	setlt	setne	settexteq	settextge	settextgt	settextle
settextlt	settextne	settobpchar	settonumber	settonvarchar2	settotext	settovarchar
textseteq	textsetge	textsetgt	textsetle	textsetlt	textsetne	gb18030_2022_to_utf8
utf8_to_gb18030_2022	array_to_nesttable	array_to_indexby_int_table	nesttable_to_array	indexbytableint_to_array	array_to_nesttable	array_to_indexby_int_table
zhs16gbk_to_utf8	utf8_to_zhs16gbk	zhs16gbk_to_gb18030	gb18030_to_zhs16gbk	zhs16gbk_to_gb18030_2022	gb18030_2022_to_zhs16gbk	-

Internal functions for aggregation operations

array_agg_finalfn	array_agg_transfn	bytea_string_agg_finalfn	bytea_string_agg_transfn	date_list_agg_noarg2_transfn	date_list_agg_transfn	float4_list_agg_noarg2_transfn
float4_list_agg_transfn	float8_list_agg_noarg2_transfn	float8_list_agg_transfn	int2_list_agg_noarg2_transfn	int2_list_agg_transfn	int4_list_agg_noarg2_transfn	int4_list_agg_transfn
int8_list_agg_noarg2_transfn	int8_list_agg_transfn	interval_list_agg_noarg2_transfn	interval_list_agg_transfn	list_agg_finalfn	list_agg_noarg2_transfn	list_agg_transfn
median	median_float8_finalfn	median_interval_finalfn	median_transfn	mode_final	numeric_list_agg_noarg2_transfn	numeric_list_agg_transfn
ordered_set_transition	percentile_cont_float8_final	percentile_cont_interval_final	string_agg_finalfn	string_agg_transfn	timestamp_list_agg_noarg2_transfn	timestamp_list_agg_transfn
timestamptz_list_agg_noarg2_transfn	timestamptz_list_agg_transfn	checksumtext_agg_transfn	json_agg_transfn	json_agg_finalfn	json_object_agg_transfn	json_object_agg_finalfn

Hash internal functions

hashbeginscan	hashbuild	hashbuildempty	hashbulkdelete	hashcostestimate	hashendscan	hashgetbitmap
hashgettuple	hashinsert	hashmarkpos	hashmerge	hashrescan	hashrestrpos	hashvacuumcleanup
hashvarlena	jsonb_hash	-	-	-	-	-

Internal functions of the B-tree index

cbtreebuild	cbtreecanreturn	cbtreecostestimate	cbtreegetbitmap	cbtreegettuple	btbeginscan	btbuild
btbuildempty	btbulkdelete	btcanreturn	btcostestimate	btendscan	btfloat4sortsupport	btfloat8sortsupport
btgetbitmap	btgettuple	btinsert	btint2sortsupport	btint4sortsupport	btint8sortsupport	btmarkpos
btmerge	btnamesortsupport	btrescan	btrestrpos	bttextsortsupport	btvacuumcleanup	cbtreeoptions

Internal functions of the Psort index

psortbuild

psortcanreturn

psortcostestimate

psortgetbitmap

psortgettuple

Internal functions of the UB-tree index

ubtbeginscan	ubtbuild	ubtbuildempty	ubtbulkdelete	ubtcanreturn
ubtcostestimate	ubtendscan	ubtgetbitmap	ubtgettuple	ubtinsert
ubtmarkpos	ubtmerge	ubtoptions	ubtrescan	ubtrestrpos
ubtvacuumcleanup	-	-	-	-

Internal functions of the GsIVFFLAT index

ivfflatbeginscan	ivfflatbuild	ivfflatbuildempty	ivfflatbulkdelete	ivfflatinsert
ivfflatcostestimate	ivfflatendscan	ivfflatoptions	ivfflatgettuple	ivfflatvacuumcleanup
ivfflatrescan	-	-	-	-

Internal functions of the GsDiskANN index

diskannbeginscan	diskannbuild	diskannbuildempty	diskannbulkdelete	diskanninsert
diskanncostestimate	diskannendscan	diskannoptions	diskanngettuple	diskannvacuumcleanup
diskannrescan	-	-	-	-

Internal functions of the BM25 index (not supported in the current version)

gs_bm25beginscan	gs_bm25build	gs_bm25buildempty	gs_bm25bulkdelete	gs_bm25insert
gs_bm25costestimate	gs_bm25endscan	gs_bm25options	gs_bm25gettuple	gs_bm25vacuumcleanup
gs_bm25rescan	-	-	-	-

PL/pgSQL internal function

plpgsql_inline_handler

Foreign table-related internal functions

dist_fdw_handler	roach_handler	streaming_fdw_handler	dist_fdw_validator	file_fdw_handler	file_fdw_validator	log_fdw_handler
gc_fdw_handler	gc_fdw_validator	dblink_fdw_handler	dblink_fdw_validator	-	-	-

Internal function related to data skew optimization

distributed_count

Internal functions related to table statistics

pgxc_get_stat_dirty_tables

pgxc_stat_dirty_tables

get_global_stat_all_tables

get_summary_stat_all_tables

Functions for reading data remotely

gs_read_block_from_remote is used to read the pages of a non-segment-page table file. By default, only the initial user can view the data. Other users can use the data only after being granted permissions.

gs_read_segment_block_from_remote is used to read the pages of a segment-page table file. By default, only the initial user can view the data. Other users can use the data only after being granted permissions.

Functions for reading files remotely

gs_read_file_size_from_remote is used to read the size of a specified file. Before using the gs_repair_file function to repair a file, you need to obtain the size of the file from the remote end to verify the missing file information and repair the missing files one by one. By default, only the initial user can view the data. Other users can use the data only after being granted permissions.

gs_read_file_from_remote is used to read a specified file. After obtaining the file size by using the gs_read_file_size_from_remote function, gs_repair_file reads the remote file segment by segment using this function. By default, only the initial user can view the data. Other users can use the data only after being granted permissions.

Auxiliary functions for incrementally rebuilding other standby or cascaded standby DNs using the standby DN.

gs_standby_incremental_filemap_create is used to create a temporary filemap file for incremental rebuilding on the standby DN. The filemap file is used to store the path and size of the data to be transferred during the incremental rebuilding. This API can be called only when the initial user is used and application is gs_rewind.

gs_standby_incremental_filemap_insert is used to insert file information into a specified temporary filemap file. The file information includes the file path, transfer start point, length of data to be transferred at a time, and rebuild flag bit. This API can be called only when the initial user is used and application is gs_rewind.

gs_standby_incremental_filemap_execute is used to obtain file information stored in a specified temporary filemap file and delete the specified filemap file for data transmission during incremental standby DN rebuilding. This API can be called only when the initial user is used and application is gs_rewind.

Ledger database function

get_dn_hist_relhash

View-related reference functions

adm_hist_sqlstat_func

adm_hist_sqlstat_idlog_func

adm_hist_sqltext_func

gs_txn_snapshot system catalog maintenance function

gs_insert_delete_txn_snapshot is used to maintain the gs_txn_snapshot system catalog of each node in distributed GTM-Lite mode. Only system administrators can call gs_insert_delete_txn_snapshot.