GATE CSE 2022
Q51.
Consider a relation R( A, B, C, D, E ) with the following three functional dependencies.AB \rightarrow C;BC \rightarrow D; C \rightarrow E; The number of superkeys in the relation R is .Q52.
Consider the relational database with the following four schemas and their respective instances.The number of rows returned by the above SQL query is ___Q53.
Let R_i(z) and W_i(z) denote read and write operations on a data element z by a transaction T_i, respectively. Consider the schedule S with four transactions.S: R_4(x)R_2(x)R_3(x)R_1(y)W_1(y)W_2 (x)W_3 (y)R_4(y) Which one of the following serial schedules is conflict equivalent to S?Q55.
Consider the data transfer using TCP over a 1 Gbps link. Assuming that the maximum segment lifetime (MSL) is set to 60 seconds, the minimum number of bits required for the sequence number field of the TCP header, to prevent the sequence number space from wrapping around during the MSL is