Updated on 2025-07-22 GMT+08:00

PG_AMPROC

PG_AMPROC records information about the support procedures associated with the access method operator families. There is one row for each support procedure that belongs to an operator family.

Table 1 PG_AMPROC columns

Name

Type

Reference

Description

oid

oid

-

Row identifier (hidden attribute, which must be specified).

amprocfamily

oid

oid in PG_OPFAMILY

Operator family of this entry.

amproclefttype

oid

oid in PG_TYPE

Left-hand input data type of the associated operator. For details about the possible values and their description, see Data Type.

amprocrighttype

oid

oid in PG_TYPE

Right-hand input data type of the associated operator. For details about the possible values and their description, see Data Type.

amprocnum

smallint

-

Support procedure number.

amproc

regproc

proname in PG_PROC

OID of the procedure.

The usual interpretation of the amproclefttype and amprocrighttype columns is that they identify the left and right input types of the operator(s) that a particular support procedure supports. For some access methods, these match the input data type(s) of the support procedure itself; for others not. There is a notion of "default" support procedures for an index, which are those with amproclefttype and amprocrighttype both equal to the index opclass's opcintype.