Well first I am going under the assumption that you meant records instead of tables. Unless you have 3000 tables that are numbered 1,2,3,4.
So assuming you meant record and assuming you are talking about an id colunm in a table, I asked my question because YOU are not really searching throught them, the server is, and what difference could it possibly make if the id is 300 or 56?
And I asked the question because if you reset all your id values...it could upset data in other tables that rely on the id field.
If you REALLY wanted to do it you could select all the data except the field you want to reset into a file...drop the table...reload the data. But that just seems kinda silly