In ASA 9.0, it introduced a "START AT" for selecting records from the
middle of a selected recordset, for example,
SELECT TOP 20 START AT 1000 * FROM mytable ORDER BY table_id
to get the records from row number 1000 to 1020, usually used in web
paging. This is great tool. It allows me to do web paging easily,
without the stored procedure approach many have suggested in the past.
But I have some questions on how it work.

Can someone please explain how it work internally? Does it use a
temporary table? If my selection has 100,000 records, how much
performance difference between selecting the first 20 records and the
last 20 records? Again, for the 100,000 recrod number, will I see the
system memory usage spike different for the first 20 records and for
the last 20 records?

I have searched the new groups for answers. The cloest one I can find
is the thread with subject "Positioned retrieval in ASA like Mysql?",
where Robert Waywell (rwaywell (AT) ianywhere (DOT) com) answered other related
questions in detail, but not the questions I have. Can someone knows
the internal working mechanism please answer these questions? Thanks
in advance.


-Zihong