52.5. 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 52.5. pg_amproc Columns

   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

   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.