使用DBCC Page命令查看Page的context，Page Header各个字段的含义
dbcc traceon(3604) dbcc page(DBID,TableID,IndexID,PartitionNumber)
Page Header Example
PAGE HEADER: Page @0x000000024F382000 m_pageId = (1:164) m_headerVersion = 1 m_type = 1 m_typeFlagBits = 0x0 m_level = 0 m_flagBits = 0x0 m_objId (AllocUnitId.idObj) = 86 m_indexId (AllocUnitId.idInd) = 256 Metadata: AllocUnitId = 72057594043564032 Metadata: PartitionId = 72057594039173120 Metadata: IndexId = 1 Metadata: ObjectId = 277576027 m_prevPage = (1:163) m_nextPage = (1:165) pminlen = 8008 m_slotCnt = 1 m_freeCnt = 83 m_freeData = 8107 m_reservedCnt = 0 m_lsn = (34:33:14) m_xactReserved = 0 m_xdesId = (0:0) m_ghostRecCnt = 0 m_tornBits = 0 DB Frag ID = 1
1，m_pageId = (1:164)
Page所在的File ID 和Page ID
2，m_type = 1
| PageType | PageType_Desc |
| 1 | Data Page |
| 2 | Index Page |
| 3 | LOB |
| 4 | LOB |
| 8 | GAM |
| 9 | SGAM |
| 10 | IAM |
| 11 | PFS |
| 13 | Boot |
| 15 | FileHeader |
| 16 | DCM |
| 17 | BCM |
3，m_level = 0
Page 在Index 中所处的Level，m_level=0，表示处于Leaf Level。
对于Heap，m_level=0表示的是Data Page；
对于Clustered index，m_level=0表示的是Data Page；
对于Nonclustered index，m_level=0表示的leaf level node.
4，用于计算AllocUnitId
m_objId (AllocUnitId.idObj) = 86
m_indexId (AllocUnitId.idInd) = 256
详细信息请参考：Inside the Storage Engine: How are allocation unit IDs calculated?
5, Metadata
Metadata: AllocUnitId = 72057594043564032
Metadata: PartitionId = 72057594039173120
Metadata: IndexId = 1
Metadata: ObjectId = 277576027
6, page的chain pointer
m_prevPage = (1:163) --Previous Page (FileID : PageID)
m_nextPage = (1:165) --Next Page(FileID:PageID)
7, Other
pminlen = 8008 --定长数据所占的字节数为8008个字节
m_slotCnt = 1 --页面中的数据的行数，每页1条记录
m_freeCnt = 83 --页面中剩余的空间，还剩83字节的空间
m_freeData = 8107 --页面空闲空间的位置在8107Byte，一个页面8KB等于8192字节
m_reservedCnt = 0 --活动事务释放的字节数
m_lsn = (34:33:14) --Log Sequence No
m_xactReserved = 0 --最新加入到m_reservedCnt field的字节数
m_xdesId = (0:0) --添加到m_reservedCnt的最近的事务id
m_ghostRecCnt = 0 --ghost Record count
m_tornBits = 0 --This holds either the page checksum or the bits that were displaced by the torn-page protection bits –
depending on what form of page protection is turnde on for the database.
参考文档：
Inside the Storage Engine: How are allocation unit IDs calculated?
Inside the Storage Engine: Anatomy of a page
笔记17 DBCC IND()非常详细解释加dbcc page([GPOSDB],1,119,3)非常详细解释 2013-1-20