52.5. pg_amproc

pg_amproc

The catalog pg_amproc stores information about support functions associated with access method operator families. There is one row for each support function belonging to an operator family.

Column Type Description
oid `oid` Row identifier
amprocfamily `oid` (references pg_opfamily.oid) The operator family this entry is for
amproclefttype `oid` (references pg_type.oid) Left-hand input data type of associated operator
amprocrighttype `oid` (references pg_type.oid) Right-hand input data type of associated operator
amprocnum `int2` Support function number
amproc `regproc` (references pg_proc.oid) OID of the function

Column Type

Description

oid oid

Row identifier

amprocfamily oid (references pg_opfamily.oid)

The operator family this entry is for

amproclefttype oid (references pg_type.oid)

Left-hand input data type of associated operator

amprocrighttype oid (references pg_type.oid)

Right-hand input data type of associated operator

amprocnum int2

Support function number

amproc regproc (references pg_proc.oid)

OID of the function

: pg_amproc Columns

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