The most expensive query
What’s the most expensive query you can think of? How about this one - USPS money orders are sold throughout the United States at numerous post office locations. Each money order has a unique ID number, and while there’s no data on how many money orders are sold annually, you’d assume that finding out about the status of the money order is running a SELECT query on some large table that has that money_order_id as unique index.
How long would that query take?
Well, for one, a trip to the post office (20 minutes sound reasonable, but your mileage may vary). You have to physically request Form 6401, as there’s no option to pre-fill it online. So make it another 10 minutes at postal window.
Then it takes $5, as specified in the USPS money order rules. After that the filled 6401 travels to some place in Iowa, which would get back to you two weeks later in an official letter from some kind of USPS database query execution department.
Total cost: 2 weeks + 20 minutes + 10 minutes + $5.00
February 29th, 2008 at 7:40 am #bob
Perhaps the cost is in the serialization, not query execution per se..