易截截图软件、单文件、免安装、纯绿色、仅160KB

SQL SERVER 2005 页面文件头部结构

       Next up in the Inside the Storage Engine series is a discussion of page structure. Pages exist to store records. A database page is an 8192-byte (8KB) chunk of a database data file. They are aligned on 8KB boundaries within the data files, starting at byte-offset 0 in the file.
Here's a picture of the basic structure
Header
The page header is 96 bytes long. What I'd like to do in this section is take an example page header dump from DBCC PAGE and explain what all the fields mean. I'm using the database from the page split post and I've snipped off the rest of the DBCC PAGE output.
DBCC
TRACEON (3604)DBCC
PAGE ('pagesplittest', 1, 143, 1);GO
m_pageId = (1:143)                   m_headerVersion = 1                  m_type = 1
m_typeFlagBits = 0x4                 m_level = 0                          m_flagBits = 0x200
m_objId (AllocUnitId.idObj) = 68     m_indexId (AllocUnitId.idInd) = 256 
Metadata: AllocUnitId = 72057594042384384                                
Metadata: PartitionId = 72057594038386688                                 Metadata: IndexId = 1
Metadata: ObjectId = 2073058421      m_prevPage = (0:0)           &


相关文档:

SQL 优化经验总结34条

(1) 选择最有效率的表名顺序(只在基于规则的优化器中有效):
ORACLE 的解析器按照从右到左的顺序处理from子句中的表名,from子句中写在最后的表(基础表 driving table)将被最先处理,在from子句中包含多个表的情况下,你必须选择记录条数最少的表作为基础表。如果有3个以上的表连接查询, 那就需要选择交叉表(intersectio ......

动态SQL

Sample1:
/* Variable Declaration */
DECLARE @EmpID AS SMALLINT
DECLARE @SQLQuery AS NVARCHAR(500)
/* Build and Execute a Transact-SQL String with a single parameter value Using EXECUTE Command */
SET @EmpID = 1001
SET @SQLQuery = 'SELECT * from tblEmployees WHERE EmployeeID = ' + CAST(@EmpID A ......

尽量不要拼凑Sql语句,用参数来防注入

    如果是类似"select   *   from   user   where   uid="+uid +"  and   pwd="+pwd 很容易出问题
    使用   SQLParamenter      
    把你的SQL语句写成   类似存储过程   ......

预防SQL注入攻击之我见

1、 SQL注入攻击的本质:让客户端传递过去的字符串变成SQL语句,而且能够被执行。
2、 每个程序员都必须肩负起防止SQL注入攻击的责任。
  说起防止SQL注入攻击,感觉很郁闷,这么多年了大家一直在讨论,也一直在争论,可是到了现在似乎还是没有定论。当不知道注入原理的时候会觉得很神奇,怎么就被注入了呢? ......

一个SQL面试题

 题目要求
阿里baba的面试题
有三个表
    学生表  S 
          SID  SNAME
  教师课表 T 
          TID  TNAME  TCL
  成绩表  SC &n ......
© 2009 ej38.com All Rights Reserved. 关于E健网联系我们 | 站点地图 | 赣ICP备09004571号