51.5. 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.

Table 51.5. pg_amproc Columns

Name Type References Description
oid oid Row identifier
amprocfamily oid pg_opfamily .oid The 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 int2 Support function number
amproc regproc pg_proc .oid OID of the function

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 .