lation R on a set S, defined as x R y if and only if y R x. This is an example of? a) reflexive relation b) symmetric relation c) transitive relation d) invalid re

1 For the following database scheme Employee(empNo,fName,IName, address,DOB,sex,position.deptNo) Department(deptNo,deptName.mgrEmpNo) Project(projNo.projName,deptNo) WorksOn(empNo.projNo.dateWorked hoursWorked) ut of uestion Use relational algebra to list the names of all employees who work on the SCCS project Use S for selection and P for projection

Object-Oriented Programming and Abstract Data Types: Compatible? Object-oriented programming and abstract data structures are recent innovations. By design. Sometimes must you disagree?

What benefits does the GROUPING SETS function offer over traditional GROUP BY clauses?

Exercise 5. Regular Languages This exercise relates to languages of words over the alphabet {a, b}. For a given word w, Jwr| is the number of occurences of the character x in the word, i.e. if abaab, then Jwal W = 3 and wb| = 2. For each the languages below either (i) give a DFA that recognises the language; OR (ii) provide an argument as to why a DFA that recognises the language cannot be produced (a) All words w s.t. wa| > |w6|- (b) All words where the following equality holds: |wa| mod 2 = wo| mod 2

3,

a. The following pair of concepts are related in some way and different in another.  Explain how the concepts are similar and how they are different:  GROUP BY / ORDER BY b. The following pair of concepts are related in some way and different in another.  Explain how the concepts are similar and how they are different: WHERE / HAVING

7. List the ordered pairs in the equivalence relations produced by these partitions of ta.b.c.d.e.f.g. a) {a,b).c.d.le.f.g}. b) (a.b.c.d.ef.lg).

PLEASE TYPE ONLY IF NOT TYPE THAN DO NOT DO IT*** PLEASE DO ALL THREE QUESTIONS B, C, D***   Exercise 8.4.5: Composition and relation properties.For the following statements, provide a proof if the statement is true or give a counterexample if the statement is false. S and R are binary relations over the same domain. (b) If S is reflexive, then S∘S is reflexive. (c) If S and R are both anti-reflexive, then S∘R is anti-reflexive. (d) If S is anti-reflexive, then S∘S is anti-reflexive.

i want 4 SEQUENCES DIAGRAM from this use case:- 옷 Student incorrect extend 옷 admin add course «include include login employees evalution includes reservation time include «include>> extend extend extende extende extend y extend lack of money follow up financial situation make payment include member complete training course include online «include> basic course view employee info remove empolyee promotion employee extende view std info cash not qualified include print card has no money extend extends pass the interview includes «extend- extend choose level course exten write report apply to work receive salary modify 064 employee WRON WHEN OPM