Other System Functions

Other system functions are classified into PG-compatible functions and internal functions. These functions are not recommended. If you need to use them, contact Huawei technical support.

PG-compatible Functions and Operators

The following table lists the built-in functions and operators of GaussDB that are compatible with PG. Some functions (such as send and recv) are internal functions, and users cannot use them. Other functions are not recommended. If you need to use them, contact Huawei technical support.

_pg_char_max_length	_pg_char_octet_length	_pg_datetime_precision	_pg_expandarray	_pg_index_position	_pg_interval_type	_pg_numeric_precision
_pg_numeric_precision_radix	_pg_numeric_scale	_pg_truetypid	_pg_truetypmod	q	abs	abstime
abstimeeq	abstimege	abstimegt	abstimein	abstimele	abstimelt	abstimene
abstimeout	abstimerecv	abstimesend	aclcontains	acldefault	aclexplode	aclinsert
aclitemeq	aclitemin	aclitemout	aclremove	acos	age	akeys
any_in	any_out	anyarray_in	anyarray_out	anyarray_recv	anyarray_send	anyelement_in
anyelement_out	anyenum_in	anyenum_out	anynonarray_in	anynonarray_out	anyrange_in	anyrange_out
anytextcat	area	areajoinsel	areasel	array_agg	array_agg_finalfn	array_agg_transfn
array_append	array_cat	array_dims	array_eq	array_fill	array_ge	array_gt
array_in	array_larger	array_le	array_length	array_lower	array_lt	array_ndims
array_ne	array_out	array_prepend	array_recv	array_send	array_smaller	array_to_json
array_to_string	array_typanalyze	array_upper	arraycontained	arraycontains	arraycontjoinsel	arraycontsel
arrayoverlap	ascii	asin	atan	atan2	avals	avg
big5_to_euc_tw	big5_to_mic	big5_to_utf8	bit	bit_and	bit_in	bit_length
bit_or	bit_out	bit_recv	bit_send	bitand	bitcat	bitcmp
biteq	bitge	bitgt	bitle	bitlt	bitne	bitnot
bitor	bitshiftleft	bitshiftright	bittypmodin	bittypmodout	bitxor	bool
bool_and	bool_or	booland_statefunc	booleq	boolge	boolgt	boolin
boolle	boollt	boolne	boolor_statefunc	boolout	boolrecv	boolsend
box	box_above	box_above_eq	box_add	box_below	box_below_eq	box_center
box_contain	box_contain_pt	box_contained	box_distance	box_div	box_eq	box_ge
box_gt	box_in	box_intersect	box_le	box_left	box_lt	box_mul
box_out	box_overabove	box_overbelow	box_overlap	box_overleft	box_overright	box_recv
box_right	box_same	box_send	box_sub	bpchar	bpchar_larger	bpchar_pattern_ge
bpchar_pattern_gt	bpchar_pattern_le	bpchar_pattern_lt	bpchar_smaller	bpchar_sortsupport	bpcharcmp	bpchareq
bpcharge	bpchargt	bpchariclike	bpcharicnlike	bpcharicregexeq	bpcharicregexne	bpcharin
bpcharle	bpcharlike	bpcharlt	bpcharne	bpcharnlike	bpcharout	bpcharrecv
bpcharregexeq	bpcharregexne	bpcharsend	bpchartypmodin	bpchartypmodout	broadcast	btabstimecmp
btarraycmp	btbeginscan	btboolcmp	btbpchar_pattern_cmp	btbuild	btbuildempty	btbulkdelete
btcanreturn	btcharcmp	btcostestimate	btendscan	btfloat48cmp	btfloat4cmp	btfloat4sortsupport
btfloat84cmp	btfloat8cmp	btfloat8sortsupport	btgetbitmap	btgettuple	btinsert	btint24cmp
btint28cmp	btint2cmp	btint2sortsupport	btint42cmp	btint48cmp	btint4cmp	btint4sortsupport
btint82cmp	btint84cmp	btint8cmp	btint8sortsupport	btmarkpos	btnamecmp	btnamesortsupport
btoidcmp	btoidsortsupport	btoidvectorcmp	btoptions	btrecordcmp	btreltimecmp	btrescan
btrestrpos	btrim	bttext_pattern_cmp	bttextcmp	bttextsortsupport	bttidcmp	bttintervalcmp
btvacuumcleanup	bytea_sortsupport	bytea_string_agg_finalfn	bytea_string_agg_transfn	byteacat	byteacmp	byteaeq
byteage	byteagt	byteain	byteale	bytealike	bytealt	byteane
byteanlike	byteaout	bytearecv	byteasend	cash_cmp	cash_div_cash	cash_div_flt4
cash_div_flt8	cash_div_int2	cash_div_int4	cash_div_int8	cash_eq	cash_ge	cash_gt
cash_in	cash_le	cash_lt	cash_mi	cash_mul_flt4	cash_mul_flt8	cash_mul_int2
cash_mul_int4	cash_mul_int8	cash_ne	cash_out	cash_pl	cash_recv	cash_send
cashlarger	cashsmaller	cbrt	ceil	ceiling	center	char
char_length	character_length	chareq	charge	chargt	charin	charle
charlt	charne	charout	charrecv	charsend	chr	cideq
cidin	cidout	cidr	cidr_in	cidr_out	cidr_recv	cidr_send
cidrecv	cidsend	circle	circle_above	circle_add_pt	circle_below	circle_center
circle_contain	circle_contain_pt	circle_contained	circle_distance	circle_div_pt	circle_eq	circle_ge
circle_gt	circle_in	circle_le	circle_left	circle_lt	circle_mul_pt	circle_ne
circle_out	circle_overabove	circle_overbelow	circle_overlap	circle_overleft	circle_overright	circle_recv
circle_right	circle_same	circle_send	circle_sub_pt	clock_timestamp	close_lb	close_ls
close_lseg	close_pb	close_pl	close_ps	close_sb	close_sl	col_description
concat	concat_ws	contjoinsel	contsel	convert	convert_from	convert_to
corr	cos	cot	count	covar_pop	covar_samp	cstring_in
cstring_out	cstring_recv	cstring_send	cume_dist	current_database	current_query	current_schema
xpath_exists	current_setting	current_user	currtid	currtid2	currval	cursor_to_xml
cursor_to_xmlschema	database_to_xml	database_to_xml_and_xmlschema	database_to_xmlschema	date	date_cmp	date_cmp_timestamp
date_cmp_timestamptz	date_eq	date_eq_timestamp	date_eq_timestamptz	date_ge	date_ge_timestamp	date_ge_timestamptz
date_gt	date_gt_timestamp	date_gt_timestamptz	date_in	date_larger	date_le	date_le_timestamp
date_le_timestamptz	date_lt	date_lt_timestamp	date_lt_timestamptz	date_mi	date_mi_interval	date_mii
date_ne	date_ne_timestamp	date_ne_timestamptz	date_out	date_pl_interval	date_pli	date_recv
date_send	date_smaller	date_sortsupport	daterange_canonical	daterange_subdiff	datetime_pl	datetimetz_pl
dcbrt	decode	defined	degrees	delete	dense_rank	dexp
diagonal	diameter	dispell_init	dispell_lexize	dist_cpoly	dist_lb	dist_pb
dist_pc	dist_pl	dist_ppath	dist_ps	dist_sb	dist_sl	div
dlog1	dlog10	domain_in	domain_recv	dpow	dround	dsimple_init
dsimple_lexize	dsnowball_init	dsnowball_lexize	dsqrt	dsynonym_init	dsynonym_lexize	dtrunc
each	enum_ne	enum_out	enum_range	enum_recv	enum_send	enum_smaller
eqjoinsel	eqsel	euc_cn_to_mic	euc_cn_to_utf8	euc_jis_2004_to_shift_jis_2004	euc_jis_2004_to_utf8	euc_jp_to_mic
euc_jp_to_sjis	euc_jp_to_utf8	euc_kr_to_mic	euc_kr_to_utf8	euc_tw_to_big5	euc_tw_to_mic	euc_tw_to_utf8
every	exist	exists_all	exists_any	exp	factorial	family
fdw_handler_in	fdw_handler_out	fetchval	first_value	float4	float4_accum	float48div
float48eq	float48ge	float48gt	float48le	float48lt	float48mi	float48mul
float48ne	float48pl	float4abs	float4div	float4eq	float4ge	float4gt
float4in	float4larger	float4le	float4lt	float4mi	float4mul	float4ne
float4out	float4pl	float4recv	float4send	float4smaller	float4um	float4up
float8	float8_accum	float8_avg	float8_collect	float8_corr	float8_covar_pop	float8_covar_samp
float8_regr_accum	float8_regr_avgx	float8_regr_avgy	float8_regr_collect	float8_regr_intercept	float8_regr_r2	float8_regr_slope
float8_regr_sxx	float8_regr_sxy	float8_regr_syy	float8_stddev_pop	float8_stddev_samp	float8_var_pop	float8_var_samp
float84div	float84eq	float84ge	float84gt	float84le	float84lt	float84mi
float84mul	float84ne	float84pl	float8abs	float8div	float8eq	float8ge
float8gt	float8in	float8larger	float8le	float8lt	float8mi	float8mul
float8ne	float8out	float8pl	float8recv	float8send	float8smaller	float8um
float8up	floor	flt4_mul_cash	flt8_mul_cash	fmgr_c_validator	fmgr_internal_validator	fmgr_sql_validator
format	format_type	gb18030_to_utf8	gbk_to_utf8	generate_series	generate_subscripts	get_bit
get_byte	get_current_ts_config	get_global_gs_asp	get_large_table_name	-	-	-
gtsquery_compress	gtsquery_consistent	gtsquery_decompress	gtsquery_penalty	gtsquery_picksplit	gtsquery_same	gtsquery_union
gtsvector_compress	gtsvector_consistent	gtsvector_decompress	gtsvector_penalty	gtsvector_picksplit	gtsvector_same	gtsvector_union
gtsvectorin	gtsvectorout	has_tablespace_privilege	has_type_privilege	hash_aclitem	hashbeginscan	hashbuild
hashbuildempty	hashbulkdelete	hashcostestimate	hashendscan	hashgetbitmap	hashgettuple	hashinsert
hashint2vector	hashint4	hashint8	hashmacaddr	hashmarkpos	hashname	hashoid
hashoidvector	hashoptions	hashrescan	hashrestrpos	hashtext	hashvacuumcleanup	hashvarlena
host	hostmask	iclikejoinsel	iclikesel	icnlikejoinsel	icnlikesel	icregexeqjoinsel
icregexeqsel	icregexnejoinsel	icregexnesel	inet_client_addr	inet_client_port	inet_in	inet_out
inet_recv	inet_send	inet_server_addr	inet_server_port	inetand	inetmi	inetmi_int8
inetnot	inetor	inetpl	initcap	int2_accum	int2_avg_accum	int2_mul_cash
int2_sum	int24div	int24eq	int24ge	int24gt	int24le	int24lt
int24mi	int24mul	int24ne	int24pl	int28div	int28eq	int28ge
int28gt	int28le	int28lt	int28mi	int28mul	int28ne	int28pl
int2abs	int2and	int2div	int2eq	int2ge	int2gt	int2in
int2larger	int2le	int2lt	int2mi	int2mod	int2mul	int2ne
int2not	int2or	int2out	int2pl	int2recv	int2send	int2shl
int2shr	int2smaller	int2um	int2up	int2vectoreq	int2vectorin	int2vectorout
int2vectorrecv	int2vectorsend	int2xor	int4_accum	int4_avg_accum	int4_mul_cash	int4_sum
int42div	int42eq	int42ge	int42gt	int42le	int42lt	int42mi
int42mul	int42ne	int42pl	int48div	int48eq	int48ge	int48gt
int48le	int48lt	int48mi	int48mul	int48ne	int48pl	int4abs
int4and	int4div	int4eq	int4ge	int4gt	int4in	int4inc
int4larger	int4le	int4lt	int4mi	int4mod	int4mul	int4ne
int4not	int4or	int4out	int4pl	int4range	int4range_canonical	int4range_subdiff
int4recv	int4send	int4shl	int4shr	int4smaller	int4um	int4up
int4xor	int8	int8_avg	int8_avg_accum	int8_avg_collect	int8_mul_cash	int8_sum
int8_sum_to_int8	int8+1635:1668_accum	int82div	int82eq	int82ge	int82gt	int82le
int82lt	int82mi	int82mul	int82ne	int82pl	int84div	int84eq
int84ge	int84gt	int84le	int84lt	int84mi	int84mul	int84ne
int84pl	int8abs	int8and	int8div	int8eq	int8ge	int8gt
int8in	int8inc	int8inc_any	int8inc_float8_float8	int8larger	int8le	int8lt
int8mi	int8mod	int8mul	int8ne	int8not	int8or	int8out
int8pl	int8pl_inet	int8range	int8range_canonical	int8range_subdiff	int8recv	int8send
int8shl	int8shr	int8smaller	int8um	int8up	int8xor	integer_pl_date
inter_lb	inter_sb	inter_sl	internal_in	internal_out	interval	interval_accum
interval_avg	interval_cmp	interval_collect	interval_div	interval_eq	interval_ge	interval_gt
interval_hash	interval_in	interval_larger	interval_le	interval_lt	interval_mi	interval_mul
interval_ne	interval_out	interval_pl	interval_pl_date	interval_pl_time	interval_pl_timestamp	interval_pl_timestamptz
interval_pl_timetz	interval_recv	interval_send	interval_smaller	interval_transform	interval_um	intervaltypmodin
intervaltypmodout	intinterval	isexists	ishorizontal	iso_to_koi8r	iso_to_mic	iso_to_win1251
iso_to_win866	iso8859_1_to_utf8	iso8859_to_utf8	isparallel	isperp	isvertical	johab_to_utf8
jsonb_in	jsonb_out	jsonb_recv	jsonb_send	-	-	-
json_in	json_out	json_recv	json_send	justify_days	justify_hours	justify_interval
koi8r_to_iso	koi8r_to_mic	koi8r_to_utf8	koi8r_to_win1251	koi8r_to_win866	koi8u_to_utf8	language_handler_in
language_handler_out	latin1_to_mic	latin2_to_mic	latin2_to_win1250	latin3_to_mic	latin4_to_mic	like_escape
likejoinsel	likesel	line	line_distance	line_eq	line_horizontal	line_in
line_interpt	line_intersect	line_out	line_parallel	line_perp	line_recv	line_send
line_vertical	ln	lo_close	lo_creat	lo_create	lo_export	lo_import
lo_lseek	lo_open	lo_tell	lo_truncate	lo_unlink	log	loread
lower	lower_inc	lower_inf	lowrite	lpad	lseg	lseg_center
lseg_distance	lseg_eq	lseg_ge	lseg_gt	lseg_horizontal	lseg_in	lseg_interpt
lseg_intersect	lseg_le	lseg_length	lseg_lt	lseg_ne	lseg_out	lseg_parallel
lseg_perp	lseg_recv	lseg_send	lseg_vertical	ltrim	macaddr_and	macaddr_cmp
macaddr_eq	macaddr_ge	macaddr_gt	macaddr_in	macaddr_le	macaddr_lt	macaddr_ne
macaddr_not	macaddr_or	macaddr_out	macaddr_recv	macaddr_send	makeaclitem	masklen
max	md5 The MD5 encryption algorithm has lower security and poses security risks. Therefore, you are advised to use a more secure encryption algorithm.	mic_to_big5	mic_to_euc_cn	mic_to_euc_jp	mic_to_euc_kr	mic_to_euc_tw
mic_to_iso	mic_to_koi8r	mic_to_latin1	mic_to_latin2	mic_to_latin3	mic_to_latin4	mic_to_sjis
mic_to_win1250	mic_to_win1251	mic_to_win866	min	mktinterval	money	mul_d_interval
name	nameeq	namege	namegt	nameiclike	nameicnlike	nameicregexeq
nameicregexne	namein	namele	namelike	namelt	namene	namenlike
nameout	namerecv	nameregexeq	nameregexne	namesend	neqjoinsel	neqsel
network_cmp	network_eq	network_ge	network_gt	network_le	network_lt	network_ne
network_sub	network_subeq	network_sup	network_supeq	nlikejoinsel	nlikesel	numeric
numeric_abs	numeric_accum	numeric_add	numeric_avg	numeric_avg_accum	numeric_avg_collect	numeric_cmp
numeric_collect	numeric_div	numeric_div_trunc	numeric_eq	numeric_exp	numeric_fac	numeric_ge
numeric_gt	numeric_in	numeric_inc	numeric_larger	numeric_le	numeric_ln	numeric_log
numeric_lt	numeric_mod	numeric_mul	numeric_ne	numeric_out	numeric_power	numeric_recv
numeric_send	numeric_smaller	numeric_sortsupport	numeric_sqrt	numeric_stddev_pop	numeric_stddev_samp	numeric_sub
numeric_transform	numeric_uminus	numeric_uplus	numeric_var_pop	numeric_var_samp	numerictypmodin	numerictypmodout
numrange_subdiff	oid	oideq	oidge	oidgt	oidin	oidlarger
oidle	oidlt	oidne	oidout	oidrecv	oidsend	oidsmaller
oidvectoreq	oidvectorge	oidvectorgt	oidvectorin	oidvectorle	oidvectorlt	oidvectorne
oidvectorout	oidvectorrecv	oidvectorsend	oidvectortypes	on_pb	on_pl	on_ppath
on_ps	on_sb	on_sl	opaque_in	opaque_out	ordered_set_transition	overlaps
overlay	path	path_add	path_add_pt	path_center	path_contain_pt	path_distance
path_div_pt	path_in	path_inter	path_length	path_mul_pt	path_n_eq	path_n_ge
path_n_gt	path_n_le	path_n_lt	path_npoints	path_out	path_recv	path_send
path_sub_pt	percentile_cont	percentile_cont_float8_final	percentile_cont_interval_final	pg_char_to_encoding	pg_cursor	pg_encoding_max_length
pg_encoding_to_char	pg_extension_config_dump	-	-	pg_node_tree_in	pg_node_tree_out	pg_node_tree_recv
pg_node_tree_send	pg_prepared_statement	pg_prepared_xact	pg_notify	pg_stat_get_wal_receiver	pg_show_all_settings	pg_stat_get_bgwriter_stat_reset_time
pg_stat_get_buf_fsync_backend	pg_stat_get_checkpoint_sync_time	pg_stat_get_checkpoint_write_time	pg_stat_get_db_blk_read_time	pg_stat_get_db_blk_write_time	pg_stat_get_db_conflict_all	pg_stat_get_db_conflict_bufferpin
pg_stat_get_db_conflict_snapshot	pg_stat_get_db_conflict_startup_deadlock	pg_switch_xlog	xpath	pg_timezone_abbrevs	pg_timezone_names	pgxc_node_str
plpgsql_call_handler	plpgsql_inline_handler	plpgsql_validator	point_above	point_add	point_below	point_distance
point_div	point_eq	point_horiz	point_in	point_left	point_mul	point_ne
point_out	point_recv	point_right	point_send	point_sub	point_vert	poly_above
poly_below	poly_center	poly_contain	poly_contain_pt	poly_contained	poly_distance	poly_in
poly_left	poly_npoints	poly_out	poly_overabove	poly_overbelow	poly_overlap	poly_overleft
poly_overright	poly_recv	poly_right	poly_same	poly_send	polygon	position
positionjoinsel	positionsel	postgresql_fdw_validator	pow	power	prsd_end	prsd_headline
prsd_lextype	prsd_nexttoken	prsd_start	pt_contained_circle	pt_contained_poly	query_to_xml	query_to_xml_and_xmlschema
query_to_xmlschema	quote_ident	quote_literal	quote_nullable	radians	radius	random
range_adjacent	range_after	range_before	range_cmp	range_contained_by	range_contains	range_contains_elem
range_eq	range_ge	range_gt	range_in	range_intersect	range_le	range_lt
range_minus	range_ne	range_out	range_overlaps	range_overleft	range_overright	range_recv
range_send	range_typanalyze	range_union	rank	record_eq	record_ge	record_gt
record_in	record_le	record_lt	record_ne	record_out	record_recv	record_send
regclass	regclassin	regclassout	regclassrecv	regclasssend	regconfigin	regconfigout
regconfigrecv	regconfigsend	regdictionaryin	regdictionaryout	regdictionaryrecv	regdictionarysend	regexeqjoinsel
regexeqsel	regexnejoinsel	regexnesel	regexp_matches	regexp_replace	regexp_split_to_array	regexp_split_to_table
regoperatorin	regoperatorout	regoperatorrecv	regoperatorsend	regoperin	regoperout	regoperrecv
regopersend	regprocedurein	regprocedureout	regprocedurerecv	regproceduresend	regprocin	regprocout
regprocrecv	regprocsend	regr_avgx	regr_avgy	regr_count	regr_intercept	regr_r2
regr_slope	regr_sxx	regr_sxy	regr_syy	regtypein	regtypeout	regtyperecv
regtypesend	reltime	reltimeeq	reltimege	reltimegt	reltimein	reltimele
reltimelt	reltimene	reltimeout	reltimerecv	reltimesend	repeat	replace
reverse	RI_FKey_cascade_del	RI_FKey_cascade_upd	RI_FKey_check_ins	RI_FKey_check_upd	RI_FKey_noaction_del	RI_FKey_noaction_upd
RI_FKey_restrict_del	RI_FKey_restrict_upd	RI_FKey_setdefault_del	RI_FKey_setdefault_upd	RI_FKey_setnull_del	RI_FKey_setnull_upd	right
round	row_number	row_to_json	rpad	rtrim	scalargtjoinsel	scalargtsel
scalarltjoinsel	scalarltsel	schema_to_xml	schema_to_xml_and_xmlschema	schema_to_xmlschema	session_user	set_bit
set_byte	set_config	set_masklen	shift_jis_2004_to_euc_jis_2004	shift_jis_2004_to_utf8	sjis_to_euc_jp	sjis_to_mic
sjis_to_utf8	smgrin	smgrout	spg_kd_choose	spg_kd_config	spg_kd_inner_consistent	spg_kd_picksplit
spg_quad_choose	spg_quad_config	spg_quad_inner_consistent	spg_quad_leaf_consistent	spg_quad_picksplit	spg_text_choose	spg_text_config
spg_text_inner_consistent	spg_text_leaf_consistent	spg_text_picksplit	spgbeginscan	spgbuild	spgbuildempty	spgbulkdelete
spgcanreturn	spgcostestimate	spgendscan	spggetbitmap	spggettuple	spginsert	spgmarkpos
spgoptions	spgrescan	spgrestrpos	spgvacuumcleanup	stddev	stddev_pop	stddev_samp
string_agg	string_agg_finalfn	string_agg_transfn	strip	sum	suppress_redundant_updates_trigger	table_to_xml
table_to_xml_and_xmlschema	table_to_xmlschema	tan	text	text_ge	text_gt	text_larger
text_le	text_lt	text_pattern_ge	text_pattern_gt	text_pattern_le	text_pattern_lt	text_smaller
textanycat	textcat	texteq	texticlike	texticnlike	texticregexeq	texticregexne
textin	textlike	textne	textnlike	textout	textrecv	textregexeq
textregexne	textsend	thesaurus_init	thesaurus_lexize	tideq	tidge	tidgt
tidin	tidlarger	tidle	tidlt	tidne	tidout	tidrecv
tidsend	tidsmaller	time	time_cmp	time_eq	time_ge	time_gt
time_hash	time_in	time_larger	time_le	time_lt	time_mi_interval	time_mi_time
time_ne	time_out	time_pl_interval	time_recv	time_send	time_smaller	time_transform
timedate_pl	timemi	timepl	timestamp	timestamp_cmp	timestamp_cmp_date	timestamp_cmp_timestamptz
timestamp_eq	timestamp_eq_date	timestamp_eq_timestamptz	timestamp_ge	timestamp_ge_date	timestamp_ge_timestamptz	timestamp_gt
timestamp_gt_date	timestamp_gt_timestamptz	timestamp_hash	timestamp_in	timestamp_larger	timestamp_le	timestamp_le_date
timestamp_le_timestamptz	timestamp_lt	timestamp_lt_date	timestamp_lt_timestamptz	timestamp_mi	timestamp_mi_interval	timestamp_ne
timestamp_ne_date	timestamp_ne_timestamptz	timestamp_out	timestamp_pl_interval	timestamp_recv	timestamp_send	timestamp_smaller
timestamp_sortsupport	timestamp_transform	timestamptypmodin	timestamptypmodout	timestamptz	timestamptz_cmp	timestamptz_cmp_date
timestamptz_cmp_timestamp	timestamptz_eq	timestamptz_eq_date	timestamptz_eq_timestamp	timestamptz_ge	timestamptz_ge_date	timestamptz_ge_timestamp
timestamptz_gt	timestamptz_gt_date	timestamptz_gt_timestamp	timestamptz_in	timestamptz_larger	timestamptz_le	timestamptz_le_date
timestamptz_le_timestamp	timestamptz_lt	timestamptz_lt_date	timestamptz_lt_timestamp	timestamptz_mi	timestamptz_mi_interval	timestamptz_ne
timestamptz_ne_date	timestamptz_ne_timestamp	timestamptz_out	timestamptz_pl_interval	timestamptz_recv	timestamptz_send	timestamptz_smaller
timestamptztypmodin	timestamptztypmodout	timetypmodin	timetypmodout	timetz	timetz_cmp	timetz_eq
timetz_ge	timetz_gt	timetz_hash	timetz_in	timetz_larger	timetz_le	timetz_lt
timetz_mi_interval	timetz_ne	timetz_out	timetz_pl_interval	timetz_recv	timetz_send	timetz_smaller
timetzdate_pl	timetztypmodin	timetztypmodout	timezone (2069)	timezone (1159)	timezone (2037)	timezone (2070)
timezone (1026)	timezone (2038)	tintervalct	tintervaleq	tintervalge	tintervalgt	tintervalin
tintervalle	tintervalleneq	tintervallenge	tintervallengt	tintervallenle	tintervallenlt	tintervallenne
tintervallt	tintervalne	tintervalout	tintervalov	tintervalrecv	tintervalsame	tintervalsend
tintervalstart	to_ascii (1845)	to_ascii (1847)	to_ascii (1846)	trigger_in	trigger_out	ts_match_qv
ts_match_tq	ts_match_tt	ts_match_vq	ts_rank	ts_rank_cd	ts_rewrite	ts_stat
ts_token_type	ts_typanalyze	tsmatchjoinsel	tsmatchsel	tsq_mcontained	tsq_mcontains	tsquery_and
tsquery_cmp	tsquery_eq	tsquery_ge	tsquery_gt	tsquery_le	tsquery_lt	tsquery_ne
tsquery_not	tsquery_or	tsqueryin	tsqueryout	tsqueryrecv	tsquerysend	tsrange
tsrange_subdiff	tstzrange	tstzrange_subdiff	tsvector_cmp	tsvector_concat	tsvector_eq	tsvector_ge
tsvector_gt	tsvector_le	tsvector_lt	tsvector_ne	tsvector_update_trigger	tsvector_update_trigger_column	tsvectorin
tsvectorout	tsvectorrecv	tsvectorsend	txid_current	txid_current_snapshot	txid_snapshot_in	txid_snapshot_out
txid_snapshot_recv	txid_snapshot_send	txid_snapshot_xip	txid_snapshot_xmax	txid_snapshot_xmin	txid_visible_in_snapshot	uhc_to_utf8
unique_key_recheck	unknownin	unknownout	unknownrecv	unknownsend	-	utf8_to_big5
utf8_to_euc_cn	utf8_to_euc_jis_2004	utf8_to_euc_jp	utf8_to_euc_kr	utf8_to_euc_tw	utf8_to_gb18030	utf8_to_gbk
utf8_to_iso8859	utf8_to_iso8859_1	utf8_to_johab	utf8_to_koi8r	utf8_to_koi8u	utf8_to_shift_jis_2004	utf8_to_sjis
utf8_to_uhc	utf8_to_win	uuid_cmp	uuid_eq	uuid_ge	uuid_gt	uuid_hash
uuid_in	uuid_le	uuid_lt	uuid_ne	uuid_out	uuid_recv	uuid_send
var_pop	var_samp	varbit	varbit_in	varbit_out	varbit_recv	varbit_send
varbit_transform	varbitcmp	varbiteq	varbitge	varbitgt	varbitle	varbitlt
varbitne	varbittypmodin	varbittypmodout	varchar	varchar_transform	varcharin	varcharout
varcharrecv	varcharsend	varchartypmodin	varchartypmodout	variance	void_in	void_out
void_recv	void_send	win_to_utf8	win1250_to_latin2	win1250_to_mic	win1251_to_iso	win1251_to_koi8r
win1251_to_mic	win1251_to_win866	win866_to_iso	win866_to_koi8r	win866_to_mic	win866_to_win1251	xideq
xideqint4	xidin	xidout	xidrecv	xidsend	xml	xml_in
xml_is_well_formed	xml_is_well_formed_content	xml_is_well_formed_document	xml_out	xml_recv	xml_send	xmlagg
xmlcomment	xmlconcat2	xmlexists	xmlvalidate	-	-	-

To prevent memory bloat, it is recommended that the number of nested layers of the concat, concat_ws, textanycat, anytextcat and format functions be less than or equal to five.

Internal Functions

The following table lists the functions used by GaussDB to implement internal system functions. You are advised not to use these functions. If you need to use them, contact Huawei technical support.

spread_collect
Description: Calculates the difference between the maximum and minimum values in a certain period of time. This function is used for data collection of aggregate functions.

Parameters: s real[], v real[]

Return type: real[]
spread_final
Description: Calculates the difference between the maximum and minimum values in a certain period of time. This function is used for the final data processing of the aggregate function.

Parameter: s real[]

Return type: real
spread_internal
Description: Calculates the difference between the maximum and minimum values in a certain period of time. This function is used for the process of aggregate functions.

Parameters: s real[], v real

Return type: real[]
xidin4
Description: Inputs a 4-byte xid.

Parameter: cstring

Return type: xid32
set_hashbucket_info
Description: Sets hash bucket information.

Parameter: text

Return type: Boolean
gap_fill_internal
Description: Returns the first non-NULL value in the parameter list.

Parameter: s anyelement, v anyelement

Return type: anyelement
int1send
Description: Packs unsigned 1-byte integers into the internal data buffer stream.

Parameter: tinyint

Return type: bytea
is_contain_namespace
Description: Searches for the table name and namespace split location. If no namespace exists, 0 is returned.

Parameter: relationname name

Return type: integer
is_oid_in_group_members
Description: Not supported

Parameter: node_oid oid, group_members oidvector_extend

Return type: Boolean
isubmit_on_nodes_internal
Description: Not supported

Parameter: job bigint, node_name name, database name, what text, next_date timestamp without time zone, job_interval text

Return type: integer
listagg
Description: Specifies aggregate functions of the list type.

Parameters: smallint, text

Return type: text
log_fdw_validator
Description: Specifies validation functions.

Parameters: text[], oid

Return type: void
nvarchar2typmodin
Description: Obtains the typmod information of the varchar type.

Parameter: cstring[]

Return type: integer
nvarchar2typmodout
Description: Obtains the typmod information of the varchar type, constructs a character string, and returns the character string.

Parameter: integer

Return type: cstring
pg_nodes_memmon
Description: Not supported

Parameter: nan

Return type: innernname text, innerusedmem bigint, innertopctxt bigint, nname text, usedmem text, sharedbuffercache text, topcontext text
read_disable_conn_file
Description: Reads forbidden connection files.

Parameter: nan

Return type: disconn_mode text, disconn_host text, disconn_port text, local_host text, local_port text, redo_finished text
regex_like_m
Description: Specifies the regular expression match, which is used to determine whether a character string complies with a specified regular expression.

Parameters: text, text

Return type: Boolean
update_pgjob
Description: Updates a job.

Parameters: bigint, "char", bigint, timestamp without time zone, timestamp without time zone, timestamp without time zone, timestamp without time zone, timestamp without time zone, smallint, text

Return type: void
enum_cmp
Description: Specifies the enumeration comparison function, which is used to determine whether two enumeration classes are equal and determine their relative sizes.

Parameters: anyenum, anyenum

Return type: integer
enum_eq
Description: Specifies the enumeration comparison function, which is used to implement the equal sign (=).

Parameters: anyenum, anyenum

Return type: Boolean
enum_first
Description: Returns the first element in the enumeration class.

Parameter: anyenum

Return type: anyenum
enum_ge
Description: Specifies the enumeration comparison function, which is used to implement the greater-than sign (>) and equal sign (=).

Parameters: anyenum, anyenum

Return type: Boolean
enum_gt
Description: Specifies the enumeration comparison function, which is used to implement the greater-than sign (>).

Parameters: anyenum, anyenum

Return type: Boolean
enum_in
Description: Specifies the enumeration comparison function, which is used to determine whether an element is in an enumeration class.

Parameters: cstring, OID

Return type: anyenum
enum_larger
Description: Specifies the enumeration comparison function, which is used to implement the greater-than sign (>).

Parameters: anyenum, anyenum

Return type: anyenum
enum_last
Description: Returns the last element in the enumeration class.

Parameter: anyenum

Return type: anyenum
enum_le
Description: Specifies the enumeration comparison function, which is used to implement the less-than sign (<) and equal sign (=).

Parameters: anyenum, anyenum

Return type: Boolean
enum_lt
Description: Specifies the enumeration comparison function, which is used to implement the less-than sign (<).

Parameters: anyenum, anyenum

Return type: Boolean
enum_smaller
Description: Specifies the enumeration comparison function, which is used to implement the less-than sign (<).

Parameters: anyenum, anyenum

Return type: Boolean
node_oid_name
Description: Not supported

Parameter: oid

Return type: cstring
pg_buffercache_pages
Description: Reads data from the shared buffer.

Parameter: nan

Return type: bufferid integer, relfilenode oid, bucketid smallint, storage_type oid, reltablespace oid, reldatabase oid, relforknumber smallint, relblocknumber bigint, isdirty Boolean, usage_count smallint
pg_check_xidlimit
Description: Checks whether nextxid is greater than or equal to xidwarnlimit.

Parameter: nan

Return type: Boolean
pg_comm_delay
Description: Displays the delay status of the communications library of a single DN.

Parameter: nan

Return type: text, text, integer, integer, integer, integer
pg_comm_recv_stream
Description: Displays the receiving stream status of all communication libraries on a single DN.

Parameter: nan

Return type: text, bigint, text, bigint, integer, integer, integer, text, bigint, integer, integer, integer, bigint, bigint, bigint, bigint, bigint
pg_comm_send_stream
Description: Displays the sending stream status of all communication libraries on a single DN.

Parameter: nan

Return type: text, bigint, text, bigint, integer, integer, integer, text, bigint, integer, integer, integer, bigint, bigint, bigint, bigint, bigint
pg_comm_status
Description: Displays the communication status of a single DN.

Parameter: nan

Return type: text, integer, integer, bigint, bigint, bigint, bigint, bigint, integer, integer, integer, integer, integer
pg_log_comm_status
Description: Prints some logs on the DN.

Parameter: nan

Return type: Boolean
pg_parse_clog
Description: Parses clog to obtain the status of xid.

Parameter: nan

Return type: xid xid, status text
pg_pool_ping
Description: Sets PoolerPing.

Parameter: Boolean

Return type: SETOF Boolean
pg_pool_validate
Description: Compares fields in the pgxc_node system catalog to check whether a connection is available.

Parameter: clear Boolean, co_node_name cstring

Return type: pid bigint, node_name text
pg_resume_bkp_flag
Description: Obtains the delay Xlog flag for backup and restoration.

Parameter: slot_name name

Return type: start_backup_flag Boolean, to_delay Boolean, ddl_delay_recycle_ptr text, rewind_time text

pg_stat_get_pooler_status

Description: Queries the cache connection status in the pooler.

Parameter: nan

Return type: text, text, bigint, text, bigint, Boolean, text, bigint, bigint, bigint, bigint, bigint

**Table 1** PG_STAT_GET_POOLER_STATUS columns
Name	Type	Description
database_name	OUT text	Database name.
user_name	OUT text	Username.
tid	OUT bigint	In non-thread pool logic, this parameter indicates the ID of the thread connected to the CN. In thread pool logic, this parameter indicates the ID of the session connected to the CN.
pgoptions	OUT text	Database connection option. For details, see the options column in Connection Parameters.
node_oid	OUT bigint	OID of the node connected.
in_use	OUT boolean	Specifies whether the connection is currently used. t (true): The connection is in use. f (false): The connection is not in use.
session_params	OUT text	GUC session parameter delivered by the connection.
fdsock	OUT bigint	Local socket.
remote_pid	OUT bigint	Peer thread ID
used_count	OUT bigint	Number of reuse times of a connection.
idx	OUT bigint	Peer DN ID in the local CN.
streamid	OUT bigint	Stream ID in the physical connection.

gs_validate_ext_listen_ip

Description: Connects to DNs, queries invalid service threads on DNs connected to the original extended IP address, and clears the threads.

Parameter: For details, see Table 2.

Return value: bigint pid, text node_name

Note: This function is used only when old connections still exist on the original extended IP address after the extended IP address is reloaded. This function clears the threads where the original IP connections are located. Executing this function will clear communication listening on the extended IP address. Exercise caution when performing O&M operations. Currently, this command can be executed only by connecting to DNs and delivered by the administrator.

**Table 2** GS_VALIDATE_EXT_LISTEN_IP columns
Name	Type	Description
clear	IN cstring	Specifies whether to clear data. The options are as follows: on: clear; off: not clear.
validate_node_name	IN cstring	Name of the DN where the extended IP address connections to be cleared are located.
validate_ip	IN cstring	Extended IP address whose connections are to be cleared.
pid	OUT bigint	ID of the service thread where the extended IP address connections to be cleared are located.
node_name	OUT text	Name of the instance to which the extended IP address connections to be cleared belong.

gs_comm_listen_address_ext_info

Description: Displays the DFX information about the extended IP address configured for listen_address_ext connected to the current instance.

Parameter: nan

Return type: text node_name, text app, bigint tid, integer lwtid, bigint query_id, integer socket, text remote_ip, text remote_port, text local_ip, text local_port

**Table 3** GS_COMM_LISTEN_ADDRESS_EXT_INFO columns
Name	Type	Description
node_name	OUT text	Name of the current instance.
app	OUT text	Client connected to the DN.
tid	OUT bigint	Thread ID of the current thread.
lwtid	OUT integer	Lightweight thread ID of the current thread.
query_id	OUT bigint	Query ID of the current thread.
socket	OUT integer	Socket FD of the current physical connection.
remote_ip	OUT text	Peer IP address of the current connection.
remote_port	OUT text	Peer port of the current connection.
local_ip	OUT text	Local IP address of the current connection.
local_port	OUT text	Local port of the current connection.

gs_get_global_listen_address_ext_info()

Description: Queries the global extended IP address configuration on the CN.

Parameter: For details, see Table 4.

Return type: text node_name, text host, text port, text ext_listen_ip

Note: If the input parameter of the function is all, the function depends on the ext_ip_info static configuration file. If the file is abnormal, use the CM/OM tool to rectify the fault. In this case, the configuration cannot be updated in real time. You can set the input parameter to primary to obtain the configuration information about all primary DNs.

**Table 4** GS_GET_GLOBAL_LISTEN_ADDRESS_EXT_INFO columns
Name	Type	Description
dn_mode	IN cstring	Specifies the range of DNs to be displayed. If this parameter is set to null, all DNs are queried by default.
node_name	OUT text	DN name.
host	OUT text	Listening IP address of the DN.
port	OUT text	Listening port of the DN.
ext_listen_ip	OUT text	Extended listening IP address of the DN.

gs_get_listen_address_ext_info()

Description: Queries the extended IP address configuration of the current instance.

Parameter: nan

Return type: text node_name, text host, bigint port, text ext_listen_ip

**Table 5** GS_GET_LISTEN_ADDRESS_EXT_INFO
Name	Type	Description
node_name	OUT text	DN name.
host	OUT text	Listening IP address of the DN.
port	OUT bigint	Listening port of the DN.
ext_listen_ip	OUT text	Extended listening IP address of the DN.

psortoptions
Description: Returns the psort attribute.

Parameters: text[], Boolean

Return type: bytea
remove_job_class_depend
Description: Removes the job dependency.

Parameter: oid

Return type: void
xideq4
Description: Compares two xids to check whether they are the same.

Parameters: xid32, xid32

Return type: Boolean
xideqint8
Description: Compares two xids to check whether they are the same.

Parameters: xid, bigint

Return type: Boolean
xidlt
Description: Returns whether xid1 < xid2 is true.

Parameters: xid, xid

Return type: Boolean
xidlt4
Description: Returns whether xid1 < xid2 is true.

Parameters: xid32, xid32

Return type: Boolean
get_local_cont_query_stat
Description: Obtains the statistics of a specified continuous computing view on the local node.

Parameter: cq_id oid

Return value type: cq oid, w_in_rows int8, w_in_bytes int8, w_out_rows int8, w_out_bytes int8, w_pendings int8, w_errors int8, r_in_rows int8, r_in_bytes int8, r_out_rows int8, r_out_bytes int8, r_errors int8, c_in_rows int8, c_in_bytes int8, c_out_rows int8, c_out_bytes int8, c_pendings int8, c_errors int8
get_local_cont_query_stats
Description: Obtains all continuous computing view statistics of the local node.

Parameter: nan

Return value type: cq oid, w_in_rows int8, w_in_bytes int8, w_out_rows int8, w_out_bytes int8, w_pendings int8, w_errors int8, r_in_rows int8, r_in_bytes int8, r_out_rows int8, r_out_bytes int8, r_errors int8, c_in_rows int8, c_in_bytes int8, c_out_rows int8, c_out_bytes int8, c_pendings int8, c_errors int8
get_cont_query_stats
Description: Obtains statistics about all continuous computing views on each DN.

Parameter: nan

Return value type: node name, cq oid, w_in_rows int8, w_in_bytes int8, w_out_rows int8, w_out_bytes int8, w_pendings int8, w_errors int8, r_in_rows int8, r_in_bytes int8, r_out_rows int8, r_out_bytes int8, r_errors int8, c_in_rows int8, c_in_bytes int8, c_out_rows int8, c_out_bytes int8, c_pendings int8, c_errors int8
reset_local_cont_query_stat
Description: Resets the statistics of a specified continuous computation view on the local node.

Parameter: cq_id oid

Return type: Boolean
reset_local_cont_query_stats
Description: Resets association statistics on the specified continuous computation view of the local node.

Parameter: cq_id oid

Return type: Boolean
reset_cont_query_stats
Description: Resets the continuous computation view statistics corresponding to the STREAM object on each DN.

Parameter: stream_id oid

Return type: Boolean
check_cont_query_schema_changed
Description: Determines the schema change status of a specified continuous computation view.

Parameter: cq_id oid

Return type: Boolean
gs_get_standby_cluster_barrier_status
Description: Queries the barrier log replay information of the standby CN or DN, including the latest received barrier, LSN of the latest received barrier, barrier played back last time, and target barrier to be played back.

Parameter: nan

Return type: barrier_id text, barrier_lsn text, recovery_id text, target_id text

Note: To call this function, the user must have the SYSADMIN or OPRADMIN permission. An O&M administrator must enable operate_mode.
gs_set_standby_cluster_target_barrier_id
Description: Set the target barrier to be replayed.

Parameter: barrier_id

Return type: target_id text

Note: To call this function, the user must have the SYSADMIN or OPRADMIN permission. An O&M administrator must enable operate_mode.
gs_query_standby_cluster_barrier_id_exist
Description: Queries whether the specified barrier is received by the standby node.

Parameter: barrier_id

Return type: Boolean

Note: To call this function, the user must have the SYSADMIN or OPRADMIN permission. An O&M administrator must enable operate_mode.

standby_read_status

Description: Obtains the CSN-based snapshot information of all DNs in a cluster, the difference between the primary and standby DNs, and the CSN-based snapshot information used for the last read query on the standby node.

Parameter: nan

Return type: text, text, text, integer, bigint, bigint, bigint

**Table 6** standby_read_status columns
Name	Type	Description
name	text	DN name
type	text	DN type (primary for the primary node and standby for the standby node)
host	text	IP address used by the DN
port	integer	Port used by the DN
collected_csn	bigint	CSN-based snapshot information of the DN (For the primary node, the value is 0. For the standby node, the value is the collected CSN.)
delay	bigint	Difference between the primary and standby DNs. The unit is ms.
visited_csn	bigint	CSN information used for the last read query on the standby node. (This parameter is valid only for the standby node where the last query is executed.)

gs_shutdown_cross_region_walsenders
Description: Interrupts cross-cluster streaming replication.

Parameter: nan

Return type: void

Note: To call this function, the user must have the SYSADMIN or OPRADMIN permission. An O&M administrator must enable operate_mode.

The following stream functions exist but are not supported. You are advised not to use them.

streaming_int8_avg_gather, streaming_numeric_avg_gather, streaming_float8_avg_gather, streaming_interval_avg_gather, streaming_int8_sum_gather, and streaming_int2_int4_sum_gather
is_dblink_in_transaction
Description: Checks whether a database link corresponding to an OID is used in the current transaction.

Parameter: oid

Return type: Boolean
dblink_has_updatasent
Description: Checks whether DML statements are sent using a database link corresponding to an OID in the current transaction and are not committed.

Parameter: oid

Return type: Boolean
get_last_xmin_by_oid
Description: Obtains the maximum xmin value of all columns in a table based on the table OID.

Parameter: oid

Return type: xid
get_relid_by_relname
Description: Obtains the OID of a table based on the table name and relnamespace.

Parameter: cstring, oid

Return type: oid