Exercise 3: Assume that for the relation Sailor(sailorld, sName, rating, age) each record is 50 bytes, a
page can hold 80 records, there are 500 pages of records and the file is unordered. We want to
process the following two queries:
ii. $\sigma_{sailorld=50,000}$(Sailor)
i. $\sigma_{sailorld<50,000}$(Sailor)
Estimate the page I/Os for each query given the information in a) and b) below.
a) Assume that we have a B*-tree index on the search key sailorld with height 5, 50 index pages, the
lowest index search-key value is 1 and highest index search-key value is 100,000.
i. $\sigma_{sailorld<50000}$(Sailor)
Page I/Os:
ii. $\sigma_{sailorld=50,000}$ (Sailor)
Page I/Os:
b) Assume that we have a hash index on the search key sailorld with 50 index pages, no overflow,
the lowest index search-key value is 1 and highest index search-key value is 100,000.
i. $\sigma_{sailorld<50000}$(Sailor)
Page I/Os:
ii. $\sigma_{sailorld=50,000}$ (Sailor)
Page I/Os:
