51.45. pg_role_password
 The catalog pg_role_password records role's passwords history used to enforce authentication restrictions. 
 Unlike most system catalogs, pg_role_password is shared across all databases of a cluster: there is only one copy of pg_role_password per cluster, not one per database. 
Table 51.45. pg_role_password Columns
Column Type Description  | 
|---|
 The OID of the role  | 
 Password of the role (possibly encrypted)  | 
 Password set time  |