quote:

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Originally posted by aakcse

Hi all,

As we know that sqlengine access the row from the data pages with the help of,page header and offset, however how sqlengine will come to know if it has to access a particular column value in a row?

What is the size of Rowid RID and wht does it contains?

Regards,
a

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quote:

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Originally posted by aakcse

Thanks Mr. Ahmad,
however, my question is different, as per my understanding page contains offset with tell where the row begin and where it ends.
and I wud like to know how the sqlengine determine, particular colum data for a row in question.

for the second,I will try and google.

Thanks,
aak

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Slot 0 Column 1 Offset 0x2e Length 6

LastName = Adkins                    

Slot 0 Column 2 Offset 0x34 Length 50

FirstName =                          

Slot 0 Column 3 Offset 0x4 Length 4

Empid = 244123                       

Slot 0 Column 4 Offset 0x8 Length 4

DeptID = 244123                      

Slot 0 Column 5 Offset 0x66 Length 12

MiddleName = Gabriel Mayo            

Slot 0 Column 6 Offset 0xc Length 8

DateOfBirth = Dec 15 1960 11:08AM    

Slot 0 Column 7 Offset 0x14 Length 8

DateOfJoining = Jul 11 1992 11:19AM  
EmpSystemID = [NULL]   

quote:

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Originally posted by aakcse

Thanks for the explaination, can you put more light on this.. still I am confuse with how the sqlengine reachs the column, as the above commands are not working on my sqlserver db.

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create table employee(empid int identity(1,1),empname varchar(50),Dateofjoining datetime)

Insert into employee values('John',getdate())
Insert into employee values('Rose',getdate())
Insert into employee values('Sachin',getdate())
Insert into employee values('Ramsey',getdate())
Insert into employee values('Sharukh',getdate())
Insert into employee values('Salman',getdate())
Insert into employee values('Maria',getdate())
Insert into employee values('Janelia',getdate())
select * from sys.sysfiles
select file_id('newdb')

Declare @dbid int,@Tableid int
select @dbid=db_id(),@Tableid=object_id('Employee')
-- lists all the pages for a particular
Dbcc ind(@dbid,@Tableid,-1)
Dbcc TraceOn(3604)
--dbcc page(@dbid,fileid,pagepid,3)
--@dbid=@dbid;fileid=id of the datafile from sys.sysfiles;pagepid=pagepid from dbcc ind output where pagetype=1;
Dbcc Page(@dbid,1,158,3)