一、什麼是執行計畫An explain plan is a representation of the access path that is taken when a query is executed within Oracle.二、如何訪問資料At the physical level Oracle reads blocks of data. The smallest amount of data read is a single Oracle block, the largest is
11G中有個新特性,當表無資料時,不分配segment,以節省空間的 解決方案: 1、insert一行,再rollback就產生segment了。 該方法是在在空表中插入資料,再刪除,則產生segment。匯出時則可匯出空表。 2、設定deferred_segment_creation 參數 show parameter deferred_segment_creation NAME TYPE VALUE --
http://luobeng.blogbus.com/logs/36329526.html1、查看錶所佔空間SELECT TABLESPACE_NAME,TO_CHAR(SUM(BYTES)/(1024*1024),'999G999D999') CNT_MB FROM DBA_EXTENTS WHERE OWNER='&OWNER' AND SEGMENT_NAME='&TABLE_NAME' AND SEGMENT_TYPE
在開始-運行中輸入命令:sqlplus /NOLOG進入開啟sqlplus.exe下面步驟:SQL>connect sys/使用者口令 as sysdbaSQL>shutdown normalSQL>startup mountORACLE 常式已經啟動。Total System Global Area 293601280 bytesFixed Size 1248624 bytesVariable Size
假如資料庫網路連接串是db_wending, 密碼是 dba/123,@lk.com SQLPLUS下(密碼用一對雙引號括住): SQL> alter user u_test identified by "dba/123,@lk.com"; SQL> conn u_test/"dba/123,@lk.com"@db_wending Linux下(密碼用一對雙引號,
CREATE OR REPLACE TYPE mytable AS TABLE OF varchar2(100)CREATE OR REPLACE FUNCTION SPLIT(SRC VARCHAR2, DELIMITER VARCHAR2) RETURN MYTABLE IS PSRC VARCHAR2(500); A MYTABLE := MYTABLE(); I NUMBER := 1; -- J NUMBER := 1;BEGIN PSRC :=