Consider the function f defined below.

struct item { 
      int data; 
      struct item * next; 
}; 

int f(struct item *p) { 
      return ((p == NULL) || (p ->next == NULL) || 
        ((p->data <= p -> next -> data) && 
        f(p-> next))); 
}

For a given linked list p, the function f returns 1 if and only if

Which of the following scenarios may lead to an irrecoverable error in a database system?

Consider three data items D1, D2, and D3, and the following execution schedule of transactions T1, T2, and T3. In the diagram, R(D) and W(D) denote the actions reading and writing the data item D respectively.

Which of the following statements is correct?

Consider the following SQL query:

Select distinct a1, a2, ..., an 

From r1, r2, ..., rm 

Where P; 

For an arbitrary predicate P, this query is equivalent to which of the following relational algebra expressions?