ORACLE中系统表的用法

查看当前USER下的特定表的列：
select * from user_tab_columns utc where utc.TABLE_NAME = 'T_FORM4';

select * from user_tab_cols utc where utc.TABLE_NAME = 'T_FORM4';
查看当前用户下的DbLink:
select * from user_db_links udl where udl.db_link = 'LIFE1';
查看当前User下的表结构:
select * from user_all_tables uat where uat.table_name = 'T_FORM4_DETAIL';
查看当前USER下的VIEW:
select * from user_views;
查看当前USER下的TYPE:
select * from user_types;
查看当前USER下的属性:
select * from user_users;
查看当前USER下的触发器:
select * from user_triggers;
查看当前USER下的TableSpace:
select * from user_tablespaces;
查看当前USER下的ERROR信息:
select * from user_errors t where t.name = 'PKG_LIFE_RPT_FORM4_MTH';
计算表所占的空间:
select * from dba_segments;
select * from dba_extents;
数据词典:
select * from Dictionary;