ORACLE: Acessar dicionario de dados do oracle

SELECT * FROM SYS.user_TAB_Columns;

podendo alterar o parametro 1:

User_
All_
Dba_

podendo alterar o parametro 2 após _ :

Objects;
Tables;
Tab_Columns;
Tab_Partitions;
Indexes;
Ind_Columns;
Ind_Partitions;
Constraints;
Cons_Columns;
Sequences;
Synonyms;
Users;
Views;
Updatable_Columns;
Types;
Type_Attrs;
Type_Methods;
Nested_Tables;
Object_Tables;
Lobs;
Method_Params;
Method_Results".


___________Parametros___|_1__|_____2______|
exemplo: SELECT * FROM SYS.user_Method_Params;