当Oracel的一个新功能出来的时候，我们可能不知道所有与此功能关联的数据字典名称，

那么如何才能得到这些 meta data 的 meta data 呢？

可以通过 dicitonary 来查看：

例如，查找所有 名字里带有 memory 的 数据字典名字列表：

SQL> col table_name for a30

SQL> col comments for a80

SQL>select table_name,comments from dictionary where table_name like '%MEMORY%';

TABLE_NAME                     COMMENTS

------------------------------ --------------------------------------------------------------------------------

DBA_HIST_MEMORY_RESIZE_OPS     Memory Resize Operations History

DBA_HIST_MEMORY_TARGET_ADVICE  Memory Target Advice History

V$INMEMORY_AREA                Synonym for V_$INMEMORY_AREA

V$JAVA_LIBRARY_CACHE_MEMORY    Synonym for V_$JAVA_LIBRARY_CACHE_MEMORY

V$LIBRARY_CACHE_MEMORY         Synonym for V_$LIBRARY_CACHE_MEMORY

V$SGA_DYNAMIC_FREE_MEMORY      Synonym for V_$SGA_DYNAMIC_FREE_MEMORY

GV$MEMORY_CURRENT_RESIZE_OPS   Synonym for GV_$MEMORY_CURRENT_RESIZE_OPS

GV$MEMORY_DYNAMIC_COMPONENTS   Synonym for GV_$MEMORY_DYNAMIC_COMPONENTS

GV$MEMORY_RESIZE_OPS           Synonym for GV_$MEMORY_RESIZE_OPS

GV$MEMORY_TARGET_ADVICE        Synonym for GV_$MEMORY_TARGET_ADVICE

GV$PROCESS_MEMORY              Synonym for GV_$PROCESS_MEMORY

TABLE_NAME                     COMMENTS

------------------------------ --------------------------------------------------------------------------------

GV$PROCESS_MEMORY_DETAIL       Synonym for GV_$PROCESS_MEMORY_DETAIL

GV$PROCESS_MEMORY_DETAIL_PROG  Synonym for GV_$PROCESS_MEMORY_DETAIL_PROG

GV$RESULT_CACHE_MEMORY         Synonym for GV_$RESULT_CACHE_MEMORY

GV$INMEMORY_AREA               Synonym for GV_$INMEMORY_AREA

GV$JAVA_LIBRARY_CACHE_MEMORY   Synonym for GV_$JAVA_LIBRARY_CACHE_MEMORY

GV$LIBRARY_CACHE_MEMORY        Synonym for GV_$LIBRARY_CACHE_MEMORY

GV$SGA_DYNAMIC_FREE_MEMORY     Synonym for GV_$SGA_DYNAMIC_FREE_MEMORY

GV$SQL_SHARED_MEMORY           Synonym for GV_$SQL_SHARED_MEMORY

V$MEMORY_CURRENT_RESIZE_OPS    Synonym for V_$MEMORY_CURRENT_RESIZE_OPS

V$MEMORY_DYNAMIC_COMPONENTS    Synonym for V_$MEMORY_DYNAMIC_COMPONENTS

V$MEMORY_RESIZE_OPS            Synonym for V_$MEMORY_RESIZE_OPS

TABLE_NAME                     COMMENTS

------------------------------ --------------------------------------------------------------------------------

V$MEMORY_TARGET_ADVICE         Synonym for V_$MEMORY_TARGET_ADVICE

V$PROCESS_MEMORY               Synonym for V_$PROCESS_MEMORY

V$PROCESS_MEMORY_DETAIL        Synonym for V_$PROCESS_MEMORY_DETAIL

V$PROCESS_MEMORY_DETAIL_PROG   Synonym for V_$PROCESS_MEMORY_DETAIL_PROG

V$RESULT_CACHE_MEMORY          Synonym for V_$RESULT_CACHE_MEMORY

V$SQL_SHARED_MEMORY            Synonym for V_$SQL_SHARED_MEMORY

SQL>