I received an email recently that started with the sort of opening sentence that I see far more often than I want to:
I have come across an interesting scenario that I would like to run by you, for your opinion.
It’s not that I object to being sent interesting scenarios, it’s just that they are rarely interesting – and this wasn’t one of those rare interesting ones. On the plus side it reminded me that I hadn’t vented one of my popular rants for some time.
Here’s the problem – see if you can work out the error before you get to the rant:
“I’ve got a table and a view on that table; and I’ve got a query that is supposed to use the view. Whether I use the table or the view in query the optimizer uses the primary key on the table to access the table – but when I use the table the query takes about 30 ms, when I use the view the query takes about 903 ms”.
