How to retrieve records in reverse order?
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for news-ticker applications, like the one in Facebook, we see that as we scroll further, older news appear. Now surely the news are inserted into the table as they occur, so a normal selection would always retrieve older records earlier, whereas here the reverse occurs. I assume the way it is done is that when the user scrolls down to the end, FB sends an Ajax request with the id of the last news-id currently present in the ticker (couldn't identify for sure in Firebug, FB sends loads of data!), the PHP queries the DB, flips the result set according to the **time** column, then extracts the say next 5 records following the one with the received id. Now such tables are huge, so flipping them frequently surely takes a heavy toll on the DB. So is there any way to achieve this without flipping?