SQL Server I/O Basic

http://technet.microsoft.com/en-us/library/cc966500.aspx
http://technet.microsoft.com/en-us/library/cc917726.aspx
http://blogs.technet.com/b/josebda/archive/2009/03/31/sql-server-2008-i-o-performance.aspx

 

Microsoft SQL Server IO Internals.pptx

읽기의 물리적인 단위는 extents 이고 논리적인 읽기의 단위는 page 이다. 쓰기의 물리적인 단위는 page 이다.
그리고, 823,824 등등 오류의 정의도 볼 수 있다.

Object ID

This is the ID of the object to which the page is assigned within the schema of the database. A page can be assigned to only a single object. When the page is read from disk, the object ID is checked on the page. If the object ID does not match the expected object ID, SQL Server will generate Error 605.

SQL Server often performs its writes on page-sized, 8-KB, or larger boundaries.

Extents

SQL Server generally (except for nonmixed extents) allocates space an extent at a time. An extent is eight 8-KB pages, or 64 KB. SQL Server often performs reads in extent-sized (64 KB or 128 KB) boundaries as well.