How auto increment ID value in table maintains the next value even a row is deleted ?

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SQL-Server-2008R2

Ex: If I have table Employee with column EmpId INT(IDENTITY(1,1),EmpName VARCHAR(60)
table looks like before delete
--------- -------
EmpId EmpName
1 xxx
2 yyy

table after delete second row i.e EmpId =2
--------- -------
EmpId EmpName
1 xxx

table after insert new row
--------- -------
EmpId EmpName
1 xxx
3 zzz

Here comes my question
How this EmpId is automatically incremented as 3 instead of 2. Is there any temporary table to store the last value of Identity column ?
Or
How it is getting Identified for the next row of the table's EmpId need to given as 3?

What I have tried:

I tried Google search but result comes out related to changing the identity value using "Reseed" in SQL SERVER

Posted 25-Oct-16 22:01pm

FeroseKhan

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OriginalGriff · Answer 1 · 2016-10-25T22:18:00

Don't.
You can do it - but it's really dangerous, particularly in a multi user system like SQL.
IDENTITY columns are supposed to give a unique value to a row, not to provide a sequential number that has no gaps. If you want that, then use ROW_NUMBER (Transact-SQL)[^] instead - it provides a sequence for the current SELECT statment.

F-ES Sitecore · Answer 2 · 2016-10-25T22:20:00

The ID sequence is simply a property of the table that the database engine in question maintains, it isn't held in a table on its own. If you want to alter this number then the process is known as "re-seeding" but there are many reasons why you shouldn't alter the number unless you really have to, it is fine to have "gaps" in your IDs.

How auto increment ID value in table maintains the next value even a row is deleted ?

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