Solved Examples

Given the following Relational Calculus statement: {B l ∃ B ∈ Books (∃ A1 ∈ Authors ((AI birth tear > 1920) (∃A2 ∈ Authons (A2. birth Year > 1920 ∧ A2. binth. Yeaor > Albirth Year ∧ B. author = A2. name))) Choose the relational Algebra expressions

• Techtud Admin
• 3 months 1 day ago

• Relation Algebra

Which of the following queries returns the department numbers of those departments for which there is no courses being offered?

• Techtud Admin
• 3 months 1 day ago

• Computer Science and Information Technology

What is the maximum number of entities (A, B, C) that could be in the ternary relationship set R

• Techtud Admin
• 3 months 1 day ago

• ER Model

What is the maximum number of tupIes possible in the natural join R JOIN S?

• Techtud Admin
• 3 months 1 day ago

• JOIN

Consider the schedule as given below: S: W3(Y); R1(Y); R3(X); W1(Y); R2(Z); R1(X); W3(Z); W1(X); W2(Y)

• Techtud Admin
• 3 months 1 day ago

• Computer Science and Information Technology

In the timestamp Ordering Protocol, R - timestamp (Q) and w - time stamp (Q) are defined by the largest timestamp among the transactions with which have respectively read and written the data item Q. Consider a variant of the protocol where R - timestamp

• Techtud Admin
• 3 months 1 day ago

• Computer Science and Information Technology

Consider the following definition of a table in SQL: Create table abc ( x integer, y integer, primary key (x), foreign key (y) references abe on delete cascade

• Techtud Admin
• 3 months 1 day ago

• Computer Science and Information Technology

Recall that a predicate logic statement is contingent if its truth value depends on the choice of the universe and on the interpretations of the predicate symbol S and the constant symbol b involved. Consider the following predicate logic statements in wh

• Techtud Admin
• 4 months 2 days ago

• Computer Science and Information Technology

int a(char *p) { if(*p != '\0') { printf("%c", *p); b(p+1); b(p+1); } return 0; } int b(char *p){ if(*p != '\0') { a(p+1); printf("%c", *p); a(p+1); } return 0; } int main() { a(

• Techtud Admin
• 4 months 3 days ago

• Computer Science and Information Technology