pg_operator
The pg_operator system catalog table stores information about operators, both built-in and those defined by CREATE OPERATOR. Unused column contain zeroes. For example, oprleft is zero for a prefix operator.
| column | type | references | description | 
|---|---|---|---|
| oid | oid | Row identifier (hidden attribute, must be explicitly selected) | |
| oprname | name | Name of the operator | |
| oprnamespace | oid | pg_namespace.oid | The OID of the namespace that contains this operator | 
| oprowner | oid | pg_authid.oid | Owner of the operator | 
| oprkind | char | b= infix (both),l= prefix (left),r= postfix (right) | |
| oprcanmerge | boolean | This operator supports merge joins | |
| oprcanhash | boolean | This operator supports hash joins | |
| oprleft | oid | pg_type.oid | Type of the left operand | 
| oprright | oid | pg_type.oid | Type of the right operand | 
| oprresult | oid | pg_type.oid | Type of the result | 
| oprcom | oid | pg_operator.oid | Commutator of this operator, if any | 
| oprnegate | oid | pg_operator.oid | Negator of this operator, if any | 
| oprcode | regproc | pg_proc.oid | Function that implements this operator | 
| oprrest | regproc | pg_proc.oid | Restriction selectivity estimation function for this operator | 
| oprjoin | regproc | pg_proc.oid | Join selectivity estimation function for this operator |