Oracle DBA 經常使用查詢

1. 查詢系統全部對象

select owner, object_name, object_type, created, last_ddl_time, timestamp, status
from dba_objects
where owner=upper('scott')

–2. 查看系統全部表
select owner, table_name, tablespace_name from dba_tables

–3. 查看全部用戶的表
select owner, table_name, tablespace_name from all_tables

–4. 查看當前用戶表
select table_name, tablespace_name from user_tables

–5. 查看用戶表索引
select t.*,i.index_type from user_ind_columns t, user_indexes i where
t.index_name = i.index_name and t.table_name = i.table_name
and t.table_name = 要查詢的表

–6. 查看主鍵
select cu.* from user_cons_columns cu, user_constraints au
where cu.constraint_name = au.constraint_name
and au.constraint_type = upper('p') and au.table_name = 要查詢的表

–7. 查看惟一性約束
select column_name from user_cons_columns cu, user_constraints au
where cu.constraint_name = au.constraint_name and au.constraint_type =  upper('u')
and au.table_name = 要查詢的表

–8. 查看外鍵
select * from user_constraints c where c.constraint_type = 'r' and c.table_name = 要查詢的表
select * from user_cons_columns cl where cl.constraint_name = 外鍵名稱
select * from user_cons_columns cl where cl.constraint_name = 外鍵引用表的鍵名

–9. 查看錶的列屬性
select t.*,c.comments
from user_tab_columns t, user_col_comments c
where t.table_name = c.table_name and t.column_name = c.column_name and t.table_name = 要查詢的表

–10. 查看全部表空間
select tablespace_name from dba_data_files group by tablespace_name

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–1. 查看oracle最大鏈接數
sql>show parameter processes    #最大鏈接數

–2. 修改最大鏈接數
sql>alter system set processes=value scope=spfile
–重啓數據庫
sql>shutdown force
sql>start force

–3. 查看當前鏈接數
sql>select * from v$session where username is not null

–4. 查看不一樣用戶的鏈接數
sql>select username,count(username) from v$session where username is not null group by username #查看指定用戶的鏈接數

–5. 查看活動的鏈接數
sql>select count(*) from v$session where status='active' #查看併發鏈接數

–6. 查看指定程序的鏈接數
sql>select count(*) from v$session where program='jdbc thin client' #查看jdbc鏈接oracle的數目

–7. 查看數據庫安裝實例(dba權限)
sql>select * from v$instance

–8. 查看運行實例名
sql>show parameter instance_name

–9. 查看數據庫名
sql>show parameter db_name

–10. 查看數據庫域名
sql>show parameter db_domain

–11. 查看數據庫服務名
sql>show parameter service_names

–12. 查看全局數據庫名
sql>show parameter global

–13. 查看錶空間使用率

 

 

-- (1)

select  dbf.tablespace_name,

        dbf.totalspace  "總量(m)" ,

        dbf.totalblocks  as  "總塊數" ,

        dfs.freespace  "剩餘總量(m)" ,

        dfs.freeblocks  "剩餘塊數" ,

        (dfs.freespace / dbf.totalspace) * 100  as  "空閒比例"

   from  ( select  t.tablespace_name,

                sum (t.bytes) / 1024 / 1024 totalspace,

                sum (t.blocks) totalblocks

           from  dba_data_files t

          group  by  t.tablespace_name) dbf,

        ( select  tt.tablespace_name,

                sum (tt.bytes) / 1024 / 1024 freespace,

                sum (tt.blocks) freeblocks

           from  dba_free_space tt

          group  by  tt.tablespace_name) dfs

  where  trim(dbf.tablespace_name) = trim(dfs.tablespace_name)

-- (2)

select  t. name  "tablespace name" ,

        free_space,

        (total_space - free_space) used_space,

        total_space

   from  ( select  tablespace_name,  sum (bytes / 1024 / 1024) free_space

           from  sys.dba_free_space

          group  by  tablespace_name)  free ,

        ( select  b. name ,  sum (bytes / 1024 / 1024) total_space

           from  sys.v_$datafile a, sys.v_$tablespace b

          where  a.ts# = b.ts#

          group  by  b. name ) t

  where  free .tablespace_name = t. name

參見：http://www.cnblogs.com/linjiqin/p/3152665.html