以Oracle为例吧
Statement为一条Sql语句生成执行计划,
如果要执行两条sql语句
select colume from table where colume=1;
select colume from table where colume=2;
会生成两个执行计划
一千个查询就生成一千个执行计划!
PreparedStatement用于使用绑定变量重用执行计划
...
分类:
数据库 时间:
2014-05-22 13:44:55
阅读次数:
380
如何使用oracle 的DBMS_SQLTUNE package 来运行 Sql Tuning Advisor 进行sql 自动调优
1》。这里简单举个例子来说明DBMS_SQLTUNE 的使用
首先现执行下某个想要调优的sql,然后获取sqlid
SQL> select * from v$sqltext where sql_text like 'select * from dua...
分类:
数据库 时间:
2014-05-22 10:47:51
阅读次数:
328
1、定义 public class EntBase:where T: new() { public
List GetListDemo() { var lst = new List(); for (int i = 1; i...
分类:
其他好文 时间:
2014-05-22 03:35:38
阅读次数:
166
比较运算符> = = 大于、小于、大于(小于)等于、不等于BETWEEN
...AND...显示在某一区间的值IN(set)显示在in列表中的值,例:in(100,200)LIKE ‘张pattern’模糊查询 _ %IS
NULL判断是否为空逻辑运算符and &&多个条件同时成立or ||多...
分类:
其他好文 时间:
2014-05-22 00:51:48
阅读次数:
658
I think everyone who is interested in ecommerce
development get familiar with Magento earlier or later. It’s a very popular
platform, where a lot of m...
分类:
其他好文 时间:
2014-05-22 00:35:05
阅读次数:
555
--第一种分页(TOP方式)--select * from T_Sys_User where
User_Id in (select top 10 User_Id from T_Sys_User where User_Id not in(select
top (10*0) User_Id from T...
分类:
数据库 时间:
2014-05-21 22:44:21
阅读次数:
485
--将text替换成你要查找的内容
select name
from sysobjects o, syscomments s
where o.id = s.id
and text like '%text%'
and o.xtype = 'P'
--将text替换成你要查找的内容
SELECT ROUTINE_NAME, ROUTINE_DEFINITION
FROM INFO...
分类:
数据库 时间:
2014-05-21 14:50:04
阅读次数:
373
Description
Facer's pet cat just gave birth to a brood of little cats. Having considered the health of those lovely cats, Facer decides to make the cats to do some exercises. Facer has well designe...
分类:
其他好文 时间:
2014-05-21 10:36:57
阅读次数:
297
【题目】
Given n non-negative integers representing an elevation map where the width of each bar is 1, compute how much water it is able to trap after raining.
For example,
Given [0,1,0,2,1,0,1,3,2,1,2,1], return 6.
The above elevation map is represente...
分类:
移动开发 时间:
2014-05-21 06:44:38
阅读次数:
359
File error 3219 occurs on Microsoft SQL servers
where you are attempting to improperly restore a database with the "Restore
Files and Filegroups" comm...
分类:
数据库 时间:
2014-05-21 03:36:02
阅读次数:
427