My table has a clustered index (date, acctId, saleId) and index level is 4.
1) logical reads 4 for
select top 1 * from myTable
where date = '2014-03-21'
and acctId = 123 2) logical reads 4 for
select top 2 * from myTable
where date = '2014-03-21'
and acctId = 123
3) logical reads 6 for
select top 3 * from myTable
where date = '2014-03-21'
and acctId = 123
4) logical reads 6 for
select top 4 * from myTable
where date = '2014-03-21'
and acctId = 123
so case 1) and case 2) are obvious, but I don't understand where the extra 2 reads come from in case 3) and case 4).
There are 10+ records for acctId 123 on 3/21 and there are all on the same page! ( checked by fn_PhysLocFormater ). There is no change activity after they are bcped into the table.
Thank you in advance!
Steve