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PG_AMPROC

PG_AMPROC stores information about support procedures associated with access method operator families. There is one row for each support procedure belonging to an operator family.

Table 1 PG_AMPROC columns

Name

Type

Reference

Description

oid

oid

-

Column identifier (hidden attribute; must be explicitly selected)

amprocfamily

oid

PG_OPFAMILY.oid

Operator family this entry is for

amproclefttype

oid

PG_TYPE.oid

Left-hand input data type of associated operator

amprocrighttype

oid

PG_TYPE.oid

Right-hand input data type of associated operator

amprocnum

smallint

-

Support procedure number

amproc

regproc

PG_PROC.oid

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.