pg_amop
The pg_amop table stores information about operators associated with index access method operator classes. There is one row for each operator that is a member of an operator class.
An entry’s amopmethod must match the opfmethod of its containing operator family (including amopmethod here is an intentional denormalization of the catalog structure for performance reasons). Also, amoplefttype and amoprighttype must match the oprleft and oprright fields of the referenced pg_operator entry.
| column | type | references | description |
|---|---|---|---|
oid | oid | Row identifier (hidden attribute; must be explicitly selected) | |
amopfamily | oid | pg_opfamily.oid | The operator family that this entry is for |
amoplefttype | oid | pg_type.oid | Left-hand input data type of operator |
amoprighttype | oid | pg_type.oid | Right-hand input data type of operator |
amopstrategy | int2 | Operator strategy number | |
amoppurpose | char | Operator purpose, either s for search or o for ordering | |
amopopr | oid | pg_operator.oid | OID of the operator |
amopmethod | oid | pg_am.oid | Index access method for the operator family |
amopsortfamily | oid | pg_opfamily.oid | If an ordering operator, the B-tree operator family that this entry sorts according to; zero if a search operator |