GATE Papers >> CSE >> 2014 >> Question No 140

Consider a join (relation algebra) between relations r(R) and s(S) using the nested loop method. There are 3 buffers each of size equal to disk block size, out of which one buffer is reserved for intermediate results. Assuming size (r(R))<size(s(S)), the join will have fewer number of disk block accesses if

• (A)  relation r(R) is in the outer loop.   
• (B)  relation s(S) is in the outer loop.   
• (C)  join selection factor between r(R) and s(S) is more than 0.5   
• (D)  join selection factor between r(R) and s(S) is less than 0.5.