Other System Functions
The openGauss built-in functions and operators of are inherited from the open-source PG. For details about the following functions, see the official PG documents.
The following table lists the functions used by GaussDB Kernel to implement internal system functions. You are not advised to use these functions. If you need to use them, contact Huawei technical support.
smgreq(a smgr, b smgr)
Description: Compares two smgrs to check whether they are the same.
Parameters: smgr, smgr
Return type: Boolean
smgrne(a smgr, b smgr)
Description: Checks whether the two smgrs are different.
Parameters: smgr, smgr
Return type: Boolean
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
hs_concat
Description: Concatenates two pieces of hstore data.
Parameters: hstore, hstore
Return type: hstore
hs_contained
Description: Determines whether two hstore data records are included. The return value is of the Boolean type.
Parameters: hstore, hstore
Return type: Boolean
hs_contains
Description: Determines whether two hstore data records are included. The return value is of the Boolean type.
Parameters: hstore, hstore
Return type: Boolean
hstore
Description: Converts parameters to the hstore type.
Parameters: text, text
Return type: hstore
hstore_in
Description: Receives hstore data in string format.
Parameter: cstring
Return type: hstore
hstore_out
Description: Sends hstore data in string format.
Parameter: hstore
Return type: cstring
hstore_send
Description: Sends hstore data in bytea format.
Parameter: hstore
Return type: bytea
hstore_to_array
Description: Sends hstore data in text array format.
Parameter: hstore
Return type: text[]
hstore_to_matrix
Description: Sends hstore data in text array format.
Parameter: hstore
Return type: text[]
hstore_version_diag
Description: Sends hstore data in integer array format.
Parameter: hstore
Return type: integer
int1send
Description: Packs unsigned 1-byte integers into the internal data buffer stream.
Parameter: tinyint
Return type: bytea
isdefined
Description: Checks whether a specified key exists.
Parameters: hstore, text
Return type: Boolean
listagg
Description: aggregate function of the list type
Parameters: smallint, text
Return type: text
log_fdw_validator
Description: validate function
Parameter: text[], oid
Return type: void
nvarchar2typmodin
Description: Obtains the typmod information of varchar.
Parameter: cstring[]
Return type: integer
nvarchar2typmodout
Description: Obtains the typmod information of varchar, constructs a character string, and returns the character string.
Parameter: integer
Return type: cstring
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: 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.
Parameter: bigint, “char”, bigint, timestamp without time zone, timestamp without time zone, timestamp without time zone, timestamp without time zone, timestamp without time zone, smallint
Return type: void
enum_cmp
Description: Enumeration comparison function, which is used to determine whether two enumeration classes are equal and determine their relative sizes.
Parameter: anyenum, anyenum
Return type: integer
enum_eq
Description: Enumeration comparison function, which is used to implement the = symbol.
Parameter: anyenum, anyenum
Return type: Boolean
enum_first
Description: Returns the first element in the enumeration class.
Parameter: anyenum
Return type: anyenum
enum_ge
Description: Enumeration comparison function, which is used to implement the >= symbol.
Parameter: anyenum, anyenum
Return type: Boolean
enum_gt
Description: Enumeration comparison function, which is used to implement the > sign.
Parameter: anyenum, anyenum
Return type: Boolean
enum_in
Description: Enumeration comparison function, which is used to determine whether an element is in an enumeration class.
Parameter: cstring, oid
Return type: anyenum
enum_larger
Description: Enumeration comparison function, which is used to implement the > sign.
Parameter: anyenum, anyenum
Return type: anyenum
enum_last
Description: Returns the last element in the enumeration class.
Parameter: anyenum
Return type: anyenum
enum_le
Description: Enumeration comparison function, which is used to implement the <= symbol.
Parameter: anyenum, anyenum
Return type: Boolean
enum_lt
Description: Enumeration comparison function, which is used to implement the < symbol.
Parameter: anyenum, anyenum
Return type: Boolean
enum_smaller
Description: Enumeration comparison function, which is used to implement the < symbol.
Parameter: 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, 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 communication 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_resume_bkp_flag
Description: Obtains the delay xlong 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
psortoptions
Description: Returns the psort attribute.
Parameter: text[], boolean
Return type: bytea
xideq4
Description: Compares two values of the xid type to check whether they are the same.
Parameters: xid32, xid32
Return type: Boolean
xideqint8
Description: Compares values of the xid type and int8 type to check whether they are the same.
Parameter: xid, bigint
Return type: Boolean
xidlt
Description: Returns whether xid1 < xid2 is true.
Parameter: xid, xid
Return type: Boolean
xidlt4
Description: Returns whether xid1 < xid2 is true.
Parameters: xid32, xid32
Return type: Boolean