PG_AGGREGATE

pg_aggregate records information about aggregation functions. Each entry in pg_aggregate is an extension of an entry in pg_proc. The pg_proc entry carries the aggregate's name, input and output data types, and other information that is similar to ordinary functions.

Table 1 PG_AGGREGATE columns

Name

Type

Reference

Description

aggfnoid

regproc

PG_PROC.oid

PG_PROC OID of the aggregate function

aggtransfn

regproc

PG_PROC.oid

Transition function

aggcollectfn

regproc

PG_PROC.oid

Aggregate function

aggfinalfn

regproc

PG_PROC.oid

Final function (zero if none)

aggsortop

oid

PG_OPERATOR.oid

Associated sort operator (zero if none)

aggtranstype

oid

PG_TYPE.oid

Data type of the aggregate function's internal transition (state) data

agginitval

text

-

Initial value of the transition state. This is a text column containing the initial value in its external string representation. If this column is null, the transition state value starts out null.

agginitcollect

text

-

Initial value of the collection state. This is a text column containing the initial value in its external string representation. If this column is null, the collection state value starts out null.