However, we'll accept whatever your data shows. Just tell us what queries you used, what indexes you created, and what the timings were.
bidder bid quantity A $10 6 B $ 8 4 C $ 7 5 D $ 6 8The lowest price at which there are bids for 11 or more is $7. Thus, the 10 beenie babies are sold for $7 each. A gets 6 and B gets 4 of them, paying $42 and $28, respectively.
Now, suppose D's bid were raised to $9. The sale price would now be $9, since 11 or more are asked for at that price, but at no higher price are 11 bid for. A, the highest bidder, would get all 6 he bid for, paying $54. The remaining 4 would go to D for $36.
Now take the scenario when C also bids $8 (and D's bid is $6). The final price here is $8, since 11 or more beanie babies are taken at that price. A still gets 6, but then the remaning 4 are divided among B and C, in proportion to the number that they bid for. In this case, there are 4 beanie babies left to split among 9 bids. So B would end up with 4*(4/9) beanie babies and C would end up with 4*(5/9) beanie babies. Don't worry that these fractions don't necessarily make sense in real life, they would be resolved by some arbitrary method that you don't have to worry about.
In part (c), do we change Sally's bids?, or does she enter new bids?
Answer: Good question. Actually, we'll accept either. That is, you can perform this operation either as an UPDATE or as an INSERT. If you choose the former, note that SQL allows a subquery in a SET clause. To check out the complete syntax of UPDATE, go to sqlplus and say help update.
In general, we believe that it is permitted for the same bidder to have two or more bids in the same auction. For example, you might want to make sure you get at least one of those beenie babies, so you bid $1000 for one, but you would take all 10 if you could get them at a reasonable price, so you bid $600 for 9. (Hmm... those things sold for $5.95 originally, so the notion of ``reasonable price'' may require some explanation.)
Question:In part d, what should the format of our result be?
Answer: The output of part d should be a single number (you want the average over all the sellers, not each seller's individual average). Pay attention to the "Note" on this problem, or you'll probably get it wrong...