查找用戶和對應的表空間:===================> select username,default_tablespace from dba_users;
服務名(tnsnames.ora 里面對應 GLOBAL_DBNAME)===================> show parameter service_name
實例名 (tnsnames.ora 里對應 SID_NAME):===================> show parameter instance_name
★★★★★查找所有用戶 ===================> select * from all_users;
查詢當前用戶下的所有表 ===================> select table_name from user_tables;
★★★★★查詢所有表空間 ===================> select tablespace_name from user_tablespaces;
★★★★★★刪除用戶 ===================> drop user hwjc cascade;
★★★★★★刪除表空間及與該表空間聯系的內容和物理文件和外鍵約束
===================> drop tablespace TIEAF_SYS including contents and datafiles cascade constraints;