Question: Explore whether the following statements are true or false. Explain why. 1. [3 points] Assume that a relation schema R(A1,,An) is given and that X{A1,,An]

Explore whether the following statements are true or false. Explain why. 1. [3 points] Assume that a relation schema R(A1,,An) is given and that X{A1,,An] holds. For trn, let t[X] be the projection of t to the attributes in X,X is called a key if the following condition is fulfilled: For all relation instances rR of R holds: t1,t2rR:t1[X]=t2[X])t1=t2 2. [3 points] In Relational Algebra, the order of operations does not matter when performing a query

Step by Step Solution

There are 3 Steps involved in it

1 Expert Approved Answer

Step: 1 Unlock blur-text-image

Question Has Been Solved by an Expert!

Get step-by-step solutions from verified subject matter experts

Step: 2 Unlock

Step: 3 Unlock

Students Have Also Explored These Related Databases Questions!

need asap, in short thanks Explore whether the following statements are true or false. Explain why. 1. [3 points] Assume that a relation schema R(A1,,An) is given and that X(A1,,An] holds. For trR,...

whether the following statements are true or false. Explain why. Assume that a relation schema R(A..... An) is given and that XC (A,..... An) holds. For t Erg. let t[X] be the projection of t to the...

tax Consider the market for apple juice. In this market, the supply curve is given by QS = 10PJ 5PA and the demand curve is given by QD = 100 15PJ + 10PT , where J denotes apple juice, A denotes...

MUST BE CORRECT ANSWERS A small software company has the following simplified cashflow, funded by shareholders' equity of 20,000 and a bank overdraft of 5000: Invoiced money received 2 months after...

the following Exercise #1. A firm produces output using the technology y =11,000KL12 , where capital, K, is measured in machine-hours, labor, L, is measured in person-hours, and y denotes the yearly...

(a) In SystemVerilog, what is the difference between: (i) The ternary operator ? and if...then...else statements? [2 marks] (ii) always_ff and always_comb? [2 marks] (iii) Blocking, non-blocking and...

s1 educated (SSE) student for every three public school educated (PSE) students. Reasoning that students are not very dissimilar from threads, he suggests the following entry and exit routines be...

dee complete please help Complexity Theory (a) Defifine the set of Boolean expressions 2CNF and the language 2SAT over them. (b) For a Boolean expression in 2CNF, let G() be the directed graph with...

This question concerns lexical grammars. (a) Tree Adjoining Grammars contain two types of elementary tree. (i) What are these trees called? [1 mark] (ii) If one were building a grammar for English...

Describe, in detail, how the heapsort algorithm works. [10 marks] Show that the worst-case cost of heapsort is O(n log n). [6 marks] Would it be possible to implement a variant of heapsort based on a...

In less-developed regions in mountainous areas, small hydroelectric generators are used to serve several residences (Mackay, 1990). Assume each house uses an electric range and an electric...

Inventory turnover and number of days' sales in inventory Financial statement data for years ending December 31 for Tango Company follow: 207 20Y6 Cost of goods sold $3,695,625 $4,004,780...

For each of the following statements relating to the yield curve, indicate whether the statement is true or false. 1 . A kink ( or discontinuity ) in the normal yield curve can be due to differing...

Compared with half a century ago, adoption has become _ _ _ _ _ _ _ _ _ common, but it is more open and acceptabl e , so we probably discuss it _ _ _ _ _ _ _ . fill in the blanks more or much less or...

What would be an example of line responsibilities that have been inappropriately assumed by a staff function? What would it take for the line operations to reclaim their appropriate role?

Employee participation in organizational decision making was, as McGregor reports, viewed with skepticism at the time he was writing. Is it now more widely valued and utilized? If so, why? If not,...

Research unambiguously finds that more participative gainsharing programs outperform simple incentive schemes that lack a participative component. Why is it, then, that so many gainsharing...