上面兩個圖是插入c##scott使用者及其測試資料後的正常運行圖~~~開始介紹下過程。 1.開始——運行——cmd 輸入:sqlplus / as sysdba 串連到資料庫2.建立c##scott使用者CREATE USER c##scott IDENTIFIED BY tiger ;3.為使用者授權GRANT CONNECT,RESOURCE,UNLIMITED TABLESPACE TO c##scottCONTAINER=ALL
Steps:1. backup database TestMirror on Pricipal server2. backup database log of TestMirror on Pricipal server3. copy db and log backup files to Mirror server4. restore db with norecovery5. restore log with norecovery6. create endpoints on both
--追蹤檔案讀入到表中分析SELECT * INTO ZGSJYFROM fn_trace_gettable('E:\wxxcdbprofiler.trc', default);--某時間內,最耗時SQLselect TOP 100 SUBSTRING(Textdata,1,660) as '名稱',count(*) as '數量', sum(duration/1000) as '總執行時間ms', avg(duration/1000) as '平均執行時間ms',
1. 內串連(InnerJoin)內串連是最常見的一種串連,它頁被稱為普通串連,而E.FCodd最早稱之為自然串連。下面是ANSI SQL-92標準select * from t_institution i inner join t_teller t on i.inst_no = t.inst_nowhere i.inst_no = "5801"其中inner可以省略。等價於早期的串連文法select * from
1、能用DISTINCT的就不用GROUP BY SELECT OrderID FROM Details WHERE UnitPrice > 10 GROUP BY OrderID 可改為: SELECT DISTINCT OrderID FROM Details WHERE UnitPrice > 10 2.能用UNION ALL就不要用UNION UNION ALL不執行SELECT
1. TRIGGER簡介trigger是mysql的觸發器,當建立觸發器時,會監控特定的事件,當觸發時會啟用物件,處理trigger_stmt,即要執行的語句。比如表的新增一條記錄時,你需要更新記錄的值得總和,則可以用trigger來實現。2. Trigger建立語句CREATE TRIGGER trigger_name trigger_time trigger_event ON tbl_name FOR EACH ROW trigger_stmt
Backtround:I'm trying to set up mirroring between two sql 2008 R2 databases on different servers in my internal network, as a test run before doing the same thing with two live servers in different locations.When I actually try and switch the
經常會遇到一個會話中存在sql效能問題,但無法定位哪一個sql導致DB效能問題較高,這是我們需要對這個session進行監控可以通過dbms_monitor包來實現。首先確定要監控的會話sid及serial#,可以通過v$session視圖獲得select sid, serial#, username from v$session where ...確定session後,調用dbms_monitor包的session_trace_enable過程:SQL> exec dbms_
Background:It's fairly common for businesses to want to provide some high availability for their SQL Server databases, and one option is to have two SQL Server databases on separate machines with a SQL Server database mirrored. Microsoft provides
資料庫控制語言的功能室控制使用者對資料庫的存取許可權。使用者對某類資料具有何種操作許可權是有DBA決定的。Oracle通過GRANT陳述式完成許可權的授予,通過REVOKE陳述式完成對許可權的收回。許可權分為系統許可權和對象許可權;系統許可權是對於資料庫的許可權,對象許可權是操作資料庫對象的許可權。 建立使用者基本文法:CREATE USER