Help Center/ GaussDB/ Developer Guide(Centralized_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	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	-
i16toi1	int16	int16_bool	int16eq	int16div	int16ge	int16gt
int16in	int16le	int16lt	int16mi	int16mul	int16ne	int16out
int16pl	int16recv	int16send	numeric_bool	int2vectorin_extend	int2vectorout_extend	int2vectorrecv_extend
int2vectorsend_extend	tdigest_in	tdigest_merge	tdigest_merge_to_one	tdigest_mergep	tdigest_out	-
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_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	-	-	-	-	-

Hash internal functions

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

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 UGIN index

ugininsert	uginbeginscan	ugingetbitmap	uginrescan	uginendscan
uginbuild	uginbuildempty	uginbulkdelete	uginvacuumcleanup	ugincostestimate
uginoptions	ugin_extract_value_trgm	ugin_extract_query_trgm	ugin_trgm_consistent	ugin_trgm_triconsistent

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

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

Internal functions related to collections

array_indexby_delete	array_indexby_length	array_integer_deleteidx	array_integer_exists	array_integer_first	array_integer_last
array_integer_next	array_integer_prior	array_varchar_deleteidx	array_varchar_exists	array_varchar_first	array_varchar_last
array_varchar_next	array_varchar_prior	-	-	-	-

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
dblink_fdw_handler	dblink_fdw_validator	-	-	-	-	-

Auxiliary functions for the primary DN to remotely read the data page from the standby DN.

gs_read_block_from_remote is used to read 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 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.

Auxiliary functions for the primary DN to remotely read data files from the standby DN.

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

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.

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

AI feature functions

create_snapshot	create_snapshot_internal	prepare_snapshot_internal	prepare_snapshot	manage_snapshot_internal	archive_snapshot	publish_snapshot
purge_snapshot_internal	purge_snapshot	sample_snapshot	-	-	-	-

PKG_SERVICE functions

isubmit_on_nodes

submit_on_nodes

Other functions

to_tsvector_for_batch	value_of_percentile	disable_conn	bind_variable	job_update	job_cancel	job_finish
similar_escape	table_skewness (unavailable)	timetz_text	time_text	reltime_text	abstime_text	_pg_keysequal
analyze_query (unavailable)	analyze_workload (unavailable)	ssign_table_type	gs_comm_proxy_thread_status	gs_txid_oldestxmin	gs_ltxid	pg_stat_segment_space_info
remote_segment_space_info	set_cost_params	set_weight_params	start_collect_workload	tdigest_in	tdigest_merge	tdigest_merge_to_one
tdigest_mergep	tdigest_out	-	-	-	-	-

View-related reference functions

adm_hisadm_hist_sqltext_funct_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. In the current version, if this function is called, f is returned.