1) Consider a disk with a sector size of 1,024 byte, 2000 tracks per surface, 50 sectors per track, 5 double-sided platters, average seek time of 10 milliseconds. Suppose that a file 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. Assume the disk rotates at 5400 RPM and one track of data can be transferred per rotation.
a. How many records fit onto a block? (1 block = 1 sector)
b. How many blocks are required to store the entire file? If the file is arranged sequentially on disk, how many surfaces are needed?
c. How many records of 100 bytes each can be stored using this disk?
d. What is the time required to read a file containing 100,000 records of 100 bytes each, sequentially?
2) Assume any record can be read within 10 milliseconds. Consider a database of 16,000,000 records. How long would it take to find a record using
a. binary-search technique
b. sequential search
3)Assume #records = 30,000, disk block = 1024, rec_len = 100, unspanned, 10 records/block, key_len = 10 bytes, block_ptr_len = 6 bytes.
3.a) How many disk blocks are needed for the data?
3b) Each node of the B+ tree should be considered as an unspanned disk block.
What is the structure of a node using Alternative #2?
3.c) How many disk blocks are needed for the B+ index (assuming full nodes)?
3.d) What is the depth of the tree?
Consider a B+ tree of order d=1. Draw diagrams to show the cumulative effect of:
a. insert 10
b. insert 20
c. insert 5
d. delete 10
e. insert 50
f. insert 55
g. insert 60
its been two days and no reply from u r website its very urgent
4)
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not yet recieved answers to my questions
09-19-03, 13:13
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