（轉）如何有效的利用數據字典進行查詢

數據字典名稱是大寫的英文字符。 數據字典裏存有用戶信息、用戶的權限信息、所有數據對象信息、表的約束條件、統計分析數據庫的視圖等。 我們不能手工修改數據字典裏的信息。 壹、用戶 查看當前用戶的缺省表空間 SQLselect username,default_tablespace from user_users; 查看當前用戶的角色 SQLselect * from user_role_privs; 查看當前用戶的系統權限和表級權限 SQLselect * from user_sys_privs; SQLselect * from user_tab_privs; 二、表 查看用戶下所有的表 SQLselect * from user_tables; 查看名稱包含log字符的表 SQLselect object_name,object_id from user_objects where instr(object_name,'LOG')0; 查看某表的創建時間 SQLselect object_name,created from user_objects where object_name=upper('&table_name'); 查看某表的大小 SQLselect sum(bytes)/(1024*1024) as "size(M)" from user_segments where segment_name=upper('&table_name'); 查看放在ORACLE的內存區裏的表 SQLselect table_name,cache from user_tables where instr(cache,'Y')0; 三、索引 查看索引個數和類別 SQLselect index_name,index_type,table_name from user_indexes order by table_name; 查看索引被索引的字段 SQLselect * from user_ind_columns where index_name=upper('&index_name'); 查看索引的大小 SQLselect sum(bytes)/(1024*1024) as "size(M)" from user_segments where segment_name=upper('&index_name'); 四、序列號 查看序列號，last_number是當前值 SQLselect * from user_sequences; 五、視圖 查看視圖的名稱 SQLselect view_name from user_views; 查看創建視圖的select語句 SQLset view_name,text_length from user_views; SQLset long 2000; 說明：可以根據視圖的text_length值設定set long 的大小 SQLselect text from user_views where view_name=upper('&view_name'); 六、同義詞 查看同義詞的名稱 SQLselect * from user_synonyms; 七、約束條件 查看某表的約束條件 SQLselect constraint_name, constraint_type,search_condition, r_constraint_name from user_constraints where table_name = upper('&table_name'); SQLselect c.constraint_name,c.constraint_type,cc.column_name from user_constraints c,user_cons_columns cc where c.owner = upper('&table_owner') and c.table_name = upper('&table_name') and c.owner = cc.owner and c.constraint_name = cc.constraint_name order by cc.position; 八、存儲函數和過程 查看函數和過程的狀態 SQLselect object_name,status from user_objects where object_type='FUNCTION'; SQLselect object_name,status from user_objects where object_type='PROCEDURE'; 查看函數和過程的源代碼 SQLselect text from all_source where owner=user and name=upper('&plsql_name'); 九、觸發器 查看觸發器 set long 50000; set heading off; set pagesize 2000; select 'create or replace trigger "' || trigger_name || '"' || chr(10)|| decode( substr( trigger_type, 1, 1 ), 'A', 'AFTER', 'B', 'BEFORE', 'I', 'INSTEAD OF' ) || chr(10) || triggering_event || chr(10) || 'ON "' || table_owner || '"."' || table_name || '"' || chr(10) || decode( instr( trigger_type, 'EACH ROW' ), 0, null, 'FOR EACH ROW' ) || chr(10) , trigger_body from user_triggers;