Does SQL add the number of steps or the number of rows added to the last entry of the primary key?

Hi,


I have a datatable with the columns ID,Value,Date,Cumulative,UniqueID where Unique ID is my primary key. UniqueID is an Identity key which auto increments with every new entry.My question is 2 parts

a) Sometimes the data is inserted multiple times so does the primary key take the number of steps or the number of rows added to table to increment the Identity Column value (UniqueID) ???

b)Also there is a possibility of gap in the UniqueID because data deletion.How do I go about checking whether there is a gap in the table and how to resolve it.Do I have to delete the table and startover again when there is a gap???
Came across this page but could not figure out whether to do this when the table is created or can it be done after the table is created.
http://msdn.microsoft.com/en-us/library/aa933196(v=sql.80).aspx

Thanx in advance
Ananth

Tags: SQL Server 2005, SQL Server