1.Explain the terms seek time, rotational delay, and transfer time.
2.If you have a large ?le that is frequently scanned sequentially, explain how you would store the pages in the ?le on a disk
3.Consider again the disk speci?cations from Exercise 9.5, and suppose that a block size of 1024 bytes is chosen. Suppose that a ?le containing 100,000 records of 100 bytes each is to be stored on such a disk and that no record is allowed to span two blocks.
1. How many records ?t onto a block?
2. How many blocks are required to store the entire ?le? If the ?le is arranged sequentially on the disk, how many surfaces are needed?
3. How many records of 100 bytes each can be stored using this disk?
4. If pages are stored sequentially on disk, with page 1 on block 1 of track 1, what page is stored on block 1 of track 1 on the next disk surface? How would your answer change if the disk were capable of reading and writing from all heads in parallel?
5. What time is required to read a ?le containing 100,000 records of 100 bytes each sequentially? Again, how would your answer change if the disk were capable of reading/writing from all heads in parallel (and the data was arranged optimally)?
6. What is the time required to read a ?le containing 100,000 records of 100 bytes each in a random order? To read a record, the block containing the record has to be fetched from disk. Assume that each block request incurs the average seek time and rotational delay.
4.When does a bu?er manager write a page to disk?
5.When a page in the bu?er pool is modi?ed, how does the DBMS ensure that this change is propagated to the disk? (Explain the role of the bu?er manager as well as the modi?er of the page.)