49.5. pg_amproc

The catalog 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 49-5. pg_amproc Columns

NameTypeReferencesDescription
oidoid Row identifier (hidden attribute; must be explicitly selected)
amprocfamilyoidpg_opfamily.oidThe operator family this entry is for
amproclefttypeoidpg_type.oidLeft-hand input data type of associated operator
amprocrighttypeoidpg_type.oidRight-hand input data type of associated operator
amprocnumint2 Support procedure number
amprocregprocpg_proc.oidOID of the procedure

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 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 operator class's opcintype.