Re: Performance of Select (pk) vs Select(*) with order by

[KimSeong Loh]

select * from customers order by birthdate limit 99980,20
and
select * from customers order by birthdate limit 100000

should take close to the same time.

Even though you only need 20 rows, it still need to sort and get the first 100000 rows based on the birthdate, to get the last 20 rows in the first 100000 rows.

If you have an index on birthdate, then it might be slightly faster, since no sorting is required with a sorted index.