Computer Science

Running head : COMPUTER SCIENCE Part 1 manikin SEQ Figure \ Arabic 1 : ERD(bFigure SEQ Figure \ ARABIC 2 : kinship schemaThe above figure is described as followsIn the customer bow , cust_no is the immemorial signalise and request_num is the irrelevant nominateIn the publication req send back , request_num is the particular key , F pattern and cust_no and EPnumber argon the hostile keysIn the facility put off , Fnumber is the master(a) key and resource is the foreign keyIn the employee submit , number is the elemental keyIn the sheath plan lines tabularize , resource is the primary key , number and EPnumberIn the location table , number is the primary key and resource is the foreign keyIn the event plan table , EPnumber is the primary key and request_num resource and number atomic number 18 the foreign keys(c . Yes t he tables be in BCNF . In on the whole the tables above the relations argon built in such a fashion that tiptop key of the relations business officeally determines all the attri simplyes in the trust relationsThere is no instance where there is a key which would functionally determine a non-prime attributePart Two2 (aSELECT s .identifier , s .name , s .email , s .major , f .nameFROM Student s , Faculty fWHERE s .facid f .facid(bSELECT c .compid , c .name ,.NumOpeningsFROM guild c , positionp WHERE c .compid.compid AND.NumOpenings degree Celsius(cSELECT s .identifier , s .nameFROM Student s , Interviewer I , high hostel c , Interview int InterviewConduct icWHERE s .stdid int .stdid ANDint .interviewid ic .interviewid ANDic .interviewerid i .interviewerid ANDi .compid c .compid ANDc .compname exchangeable `NTU Corporation(dSELECT s .identifier , s .nameFROM Student s , Interviewer I , Company c , Interview int InterviewConduct ic . Positionp WHERE s .stdid int .stdid ANDin t .interviewid ic .interviewid ANDic .interv! iewerid i .interviewerid ANDi .compid c .compid ANDp .compid c .compid ANDc .compname care `NTU Corporation ANDp .desc LIKE ` programme job4Outer Join operation is useful in cases where the institution of a weak entity type exists in the database schema . abandoned the undermentioned relation the outer(prenominal) brotherhood relations come to its in safe swingEmployeeEmp_id name Dept_id Phone1 Partha 1 99999992 Harry 1 90898983 sandlike 2 89645654 Monica 1 78787895 Tom 3 8989898 DepartmentDept_id name1 Finance2 Admin3 HR4 ITIf we happen to join the dickens tables to find how many employees work for the departments , the IT department would not be shown as there is no mention to that in the employee table .

Say IT department has been introduced newly in the company , but without the outer join the IT dept would not appear at all giving an impression that it does not existThe interest is the modal value to desexualise the full outer join in illusionist and Microsoft memory access DatabaseSELECT d .name , count (e .emp_idFROM department d full outer join employee e ON d .dept_id e .dept_idGROUP BY e .emp_id(bThe place number teaching initializes the customer id to grounds increments the economic value by 100 . The trigger created gets fired at the onset of inserting a words on the customer table . The SQL query transforms the customer_id field with the sequence created . The dual table holds the value of the sequence created , it contains the incremented valueThe oracle functions and triggers do almost the same function however the point of dispute is that in triggers there is no return value whereas functions cook a return value(cThe m! otion log would entail the following in the event of arranging failureIf there is a governing body failure at 8 :43 the following would feature placeThe transaction log would block the immediate last impedimentapoint to check the statusChecking would imply which are the proceeding the system requires to commit and which ones to stadiumbackOnce it finds that proceeding 5 ,6 and 7 are labeled to be wrap backed it automatically does itThe early(a) transactions labeled other than the mentioned ones are not interpreted care at allThese form round of the most necessary transactions which needs to be roll backed in an event of failureReferences / BibliographyNavathe Elmasri (2004 . Fundamentals of Database systems , Singapore Pearson program line PAGE 9 ...If you want to get a full essay, order it on our website: OrderCustomPaper.com

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