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：
USE master
GO
CREATE DATABASE testbase2
ON
PRIMARY
(NAME = prim_sub_dat1,
FILENAME = 'G:\SQL SERVER2000\prim_sub_dat.mdf',
SIZE = 5MB,
MAXSIZE = 50MB,
FILEGROWTH = 20%),
(NAME = prim_sub_dat2,
FILENAME = 'G:\SQL SERVER2000\prim_sub_dat.ndf'
SIZE = 5MB,
MAXSIZE = 50MB,
......
Case具有两种格式。简单Case函数和Case搜索函数。
--简单Case函数
CASE sex
WHEN '1' THEN '男'
WHEN '2' THEN '女'
ELSE '其他' END
--Case搜索函数
CASE WHEN sex = '1' THEN '男'
......
下面的这些脚本都可以找到引起磁盘排序的SQL。
SELECT /*+ rule */ DISTINCT a.SID, a.process, a.serial#,
TO_CHAR (a.logon_time, 'YYYYMMDD HH24:MI:SS') LOGON, a.osuser,TABLESPACE, b.sql_text
from v$session a, v$sql b, v$sort_usage c
WHERE a.sql_address = b.address AND a.saddr = c.session_addr;
......
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？ ......
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 ......
