内部函数
GaussDB中下列函数使用了内部数据类型，用户无法直接调用，在此章节列出。
选择率计算函数
| 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 | - |
统计信息收集函数
| array_typanalyze | range_typanalyze | ts_typanalyze |
| local_rto_stat | standby_statement_history_internal | - |
排序内部功能函数
| bpchar_sortsupport | bytea_sortsupport | date_sortsupport | numeric_sortsupport | timestamp_sortsupport |
内部类型处理函数
| 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 | - | - | - | - |
聚合操作内部函数
| 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 | - | - | - | - | - |
哈希内部功能函数
| hashbeginscan | hashbuild | hashbuildempty | hashbulkdelete | hashcostestimate | hashendscan | hashgetbitmap |
| hashgettuple | hashinsert | hashmarkpos | hashmerge | hashrescan | hashrestrpos | hashvacuumcleanup |
| hashvarlena | - | - | - | - | - | - |
Btree索引内部功能函数
| 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 |
Psort索引内部函数
| psortbuild | psortcanreturn | psortcostestimate | psortgetbitmap | psortgettuple |
Ugin索引内部函数
| 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 |
Ubtree索引内部函数
| ubtbeginscan | ubtbuild | ubtbuildempty | ubtbulkdelete | ubtcanreturn |
| ubtcostestimate | ubtendscan | ubtgetbitmap | ubtgettuple | ubtinsert |
| ubtmarkpos | ubtmerge | ubtoptions | ubtrescan | ubtrestrpos |
| ubtvacuumcleanup | - | - | - | - |
GsIVFFLAT索引内部函数
| ivfflatbeginscan | ivfflatbuild | ivfflatbuildempty | ivfflatbulkdelete | ivfflatinsert |
| ivfflatcostestimate | ivfflatendscan | ivfflatoptions | ivfflatgettuple | ivfflatvacuumcleanup |
| ivfflatrescan | - | - | - | - |
GsDiskANN索引内部函数
| diskannbeginscan | diskannbuild | diskannbuildempty | diskannbulkdelete | diskanninsert |
| diskanncostestimate | diskannendscan | diskannoptions | diskanngettuple | diskannvacuumcleanup |
| diskannrescan | - | - | - | - |
BM25索引内部函数
| gs_bm25beginscan | gs_bm25build | gs_bm25buildempty | gs_bm25bulkdelete | gs_bm25insert |
| gs_bm25costestimate | gs_bm25endscan | gs_bm25options | gs_bm25gettuple | gs_bm25vacuumcleanup |
| gs_bm25rescan | - | - | - | - |
plpgsql内部函数
plpgsql_inline_handler
集合相关内部函数
| 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 | - | - | - | - |
外表相关内部函数
| 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 | - | - | - | - | - |
主DN远程读取备DN数据页辅助函数
gs_read_block_from_remote用于读取非段页式表文件的页面。默认只有初始化用户可以查看，其余用户需要赋权后才可以使用。
gs_read_segment_block_from_remote用于读取段页式表文件的页面。默认只有初始化用户可以查看，其余用户需要赋权后才可以使用。
主DN远程读取备DN数据文件辅助函数
gs_read_file_from_remote用于读取指定的文件。gs_repair_file利用gs_read_file_size_from_remote函数获取文件大小后，依赖这个函数将远端文件逐段读取。默认只有初始化用户可以查看，其余用户需要赋权后才可以使用。
gs_read_file_size_from_remote用于读取指定文件的大小。gs_repair_file函数修复文件时，要先获取远端关于这个文件的大小，用于校验本地文件缺失的文件信息，然后将缺失的文件逐个修复。默认只有初始化用户可以查看，其余用户需要赋权后才可以使用。
以备DN实例增量重建其他备或级联备DN实例辅助函数
gs_standby_incremental_filemap_create用于创建备DN增量重建临时filemap文件，用于存储当次增量重建需传输的数据路径与大小。只有初始化用户且application为gs_rewind时可以调用。
gs_standby_incremental_filemap_insert用于向指定临时filemap文件中插入文件信息，指定文件的路径、传输起始点、单次传输数据长度和rebuild标志位。只有初始化用户且application为gs_rewind时可以调用。
gs_standby_incremental_filemap_execute用于获取指定临时filemap文件中存储的文件信息并删除指定filemap，用于备DN增量重建的数据传输。只有初始化用户且application为gs_rewind时可以调用。
账本数据库函数
get_dn_hist_relhash
AI特性函数
| 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函数
| isubmit_on_nodes | submit_on_nodes | - | - | - | - | - |
其他函数
| to_tsvector_for_batch | value_of_percentile | disable_conn | bind_variable | job_update | job_cancel | job_finish |
| similar_escape | table_skewness （不可用） | timetz_text | time_text | reltime_text | abstime_text | _pg_keysequal |
| analyze_query (不可用） | analyze_workload （不可用） | assign_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 | - | - | - | - | - |
视图相关引用函数
adm_hisadm_hist_sqltext_funct_sqlstat_func
adm_hist_sqlstat_idlog_func
adm_hist_sqltext_func
gs_txn_snapshot系统表维护函数
gs_insert_delete_txn_snapshot用于GTM-Lite模式下维护全局各节点gs_txn_snapshot系统表，只有系统管理员用户才能调用，当前版本调用该函数将返回f，无实际操作。
xmltype类型相关函数
isschemavalid
