Gbase 8C system table PG_ aggregate

pg_aggregate The system table stores information about aggregate functions .pg_aggregate Every record in is one pg_proc Expansion of records inside .PG_PROC Record the name that hosts the aggregation 、 Input and output data types , And other information similar to ordinary functions .

name	type	quote	describe
aggfnoid	regproc	pg_proc.oid	Aggregate function in pg_proc Medium OID
aggkind	char		Aggregation type ： n Express “ Ordinary ” Gather , o Express “ Ordered set ” Gather , perhaps h Express “ Hypothetical set ” Gather
aggnumdirectargs	int2		The direct aggregation of an ordered set or an imaginary set （ Non aggregation ） Number of parameters , A variable array counts as a parameter . If it is equal to pronargs, The aggregation must be variable and the variable array describes the aggregation parameters and the final direct parameters . For normal aggregation, it is always zero .
aggtransfn	regproc	pg_proc.oid	Transfer function
aggcollectfn	regproc	pg_proc.oid	Set function
aggfinalfn	regproc	pg_proc.oid	Final function （ If not, it will be zero ）
aggcombinefn	regproc	pg_proc.oid	Combining functions （ If not, it will be zero ）
aggserialfn	regproc	pg_proc.oid	Serialization function （ If not, it will be zero ）
aggdeserialfn	regproc	pg_proc.oid	Deserialization function （ If not, it will be zero ）
aggmtransfn	regproc	pg_proc.oid	Forward transfer function for moving the aggregation mode （ If not, it will be zero ）
aggminvtransfn	regproc	pg_proc.oid	Reverse transfer function for mobile aggregation mode （ If not, it will be zero ）
aggmfinalfn	regproc	pg_proc.oid	The final function for mobile aggregation mode （ If not, it will be zero ）
aggfinalextra	bool		True to aggfinalfn Pass extra dummy arguments
aggmfinalextra	bool		True to aggmfinalfn Pass extra dummy arguments
aggsortop	oid	pg_operator.oid	Associated sort operators （ If not, it is 0）
aggtranstype	oid	pg_type.oid	Internal transfer and collection of aggregation functions （ state ） The data type of the data
aggtransspace	int4		Approximate average size of transition state data （ byte ）, Or zero means using a default estimate
aggmtranstype	oid	pg_type.oid	The aggregate function is used to move the internal transfer of aggregate Euclidean （ state ） The data type of the data （ If not, zero ）
aggmtransspace	int4		Approximate average size of transition state data （ byte ）, Or zero means using a default estimate
agginitval	text		The initial value of the transition state . This is a text field , It contains the external string representation of the initial value . If this field is empty , Then the transition status value starts from the null value .
agginitcollect	text		The initial value of the set state . This is a text field , Include the initial value in its external string representation . If this field is empty , Then the set state value starts from null .
aggminitval	text		Initial value of transition state for mobile aggregation mode . This is a text field , It contains the initial value expressed in its text string . If this field is empty , Then the transition status value starts from the null value .