利用DBCC PAGE查看SQL Server中的表和索引数据

16:08 2013-01-06 参考http://doc.chinaunix.net/sqlserver/200810/206034.shtml
DBCC PAGE|IND 参数

 DBCC PAGE 参数
 (
 ['database name'|database id], --can be the actual name or id of the database
 file number, --the file number where the page is found
 page number, --the page number within the file
 print option=[0|1|2|3] --display option; each option provides differing levels of information
 )
 DBCC IND 参数
 (
 ['database name'|database id], --the database to use
 table name, --the table name to list results
 index id, --an index_id from sys.indexes; -1 shows all indexes and IAMs, -2 just show IAMs
 )

一、查看表的数据
在系统表sysindexes 的列 first中保存有 filenum,pagenum 的信息(当indid为0或者1), 列first 的数据类型为binary(6), 它是以16进制的形式储的,需要进行转换. 在16进制中,每两个进制数字表示一个字节,并且是逆序排列的. 转换完成,其中前2组数表示该表所在的文件编号; 后4组表示该表所在的页码.
根据sysindexes 中的列first返回表所在的filenum 、pagenum

 declare @first binary(6)
 select @first=first from sysindexes where id=object_id('fanr_city') and indid in(0,1)
 declare @PageNum int
 select @PageNum=convert(int,substring(@first,4,1)+substring(@first,3,1)+
 substring(@first,2,1)+substring(@first,1,1))
 declare @FileNum int
 select @FileNum=convert(int,substring(@first,6,1)+substring(@first,5,1))
 select @FileNum,@PageNum

通过返回的@FileNum,@PageNum，查看表数据页结构

 DBCC TRACEON (3604)
 DBCC Page (7,1,227,1)

返回结果如下

DBCC 执行完毕。如果 DBCC 输出了错误信息，请与系统管理员联系。

PAGE: (1:227)

BUFFER:

BUF @0x03BE8618

bpage = 0x05554000                   bhash = 0x00000000                   bpageno = (1:227)
bdbid = 7                            breferences = 0                      bUse1 = 7194
bstat = 0x1c0000b                    blog = 0x212121bb                    bnext = 0x00000000

PAGE HEADER:

Page @0x05554000

m_pageId = (1:227)                   m_headerVersion = 1                  m_type = 1
m_typeFlagBits = 0x4                 m_level = 0                          m_flagBits = 0x0
m_objId (AllocUnitId.idObj) = 114    m_indexId (AllocUnitId.idInd) = 256
Metadata: AllocUnitId = 72057594045399040
Metadata: PartitionId = 72057594044350464                                 Metadata: IndexId = 0
Metadata: ObjectId = 1381579960      m_prevPage = (0:0)                   m_nextPage = (0:0)
pminlen = 92                         m_slotCnt = 0                        m_freeCnt = 8096
m_freeData = 96                      m_reservedCnt = 0                    m_lsn = (71:349:76)
m_xactReserved = 0                   m_xdesId = (0:0)                     m_ghostRecCnt = 0
m_tornBits = 0                       

Allocation Status

GAM (1:2) = ALLOCATED                SGAM (1:3) = ALLOCATED
PFS (1:1) = 0x60 MIXED_EXT ALLOCATED   0_PCT_FULL                         DIFF (1:6) = CHANGED
ML (1:7) = NOT MIN_LOGGED            

DATA:

OFFSET TABLE:

DBCC 执行完毕。如果 DBCC 输出了错误信息，请与系统管理员联系。

二、查看索引的数据

 --创建测试表，并添加索引
 USE AdventureWorks
 SELECT *
 INTO dbo.Contacts_index
 FROM Person.Contact
 CREATE INDEX FullName ON Contacts_index(LastName,FirstName)
 DBCC IND(AdventureWorks,Contacts_index,-1)

列PageFID和PagePID分别代表页所在的文件数目和数据在文件内的页数目。IndexID是在sys.indexes之中找到的索引的index_id。PageType表示页的类型，Type=1是数据页，Type=2是索引页，Type=10是保存页本身的IAM页。IndexLevel是按页数时IAM结构的级别。如果 level=0，那么就是索引的叶级别页。

 DBCC TRACEON(3604)
 DBCC PAGE(AdventureWorks,1,15056,3) WITH TABLERESULTS
 DBCC PAGE(AdventureWorks,1,14988,3) WITH TABLERESULTS

以下分别是中间级索引页15056和叶级索引页14988、14989的数据分布情况。索引条目按照索引键的值有序排列