Gbase 8C system table PG_ am

pg_am System tables store information about index access methods . Each index access method supported by the system has a row .

name	type	quote	describe
oid	oid		Row identifier （ Hidden attribute , Must be explicitly selected to display ）
amname	name		The name of the access method
amhandler	regproc	pg_proc.oid	The processor function responsible for providing information about the access method OID
amtype	char		Current always i, Represents an index access method . Other values may be allowed in the future