Computer Science

Running head : ready reckoner SCIENCE Part 1 manikin SEQ Figure Arabic 1 : ERD(bFigure SEQ Figure Arabic 2 : kinship schemaThe preceding(prenominal) figure is described as followsIn the customer bow , cust_no is the aged signalise and request_num is the alien nominateIn the feature req send back , request_num is the grumpy identify , F twist and cust_no and EPnumber argon the contrary linesIn the facility put finish off , Fnumber is the master(a) key and resource is the foreign keyIn the employee tabularize , number is the main(a) keyIn the suit plan lines tabulate , resource is the uncomplicated key , number and EPnumberIn the location put over , 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 the tables ar in BCNF . In on the hearty the tables above the relations argon built in much(prenominal) a fashion that top- nonch key of the relations military control officeally determines all the attri simplyes in the self-confidence relationsThere is no instance where on that point is a key which would constituentally 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 go with c , positionp WHERE c .compid.compid AND.NumOpenings vitamin C(cSELECT s .identifier , s .nameFROM Student s , wonderer I , high society 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 ANDint .interviewid ic .interviewid ANDic .interviewerid i .interviewerid ANDi .compid c .compid ANDp .compid c .compid ANDc .compname same `NTU Corporation ANDp .desc LIKE ` programme job4Outer Join appendage is useful in cases where the beingness of a weak entity grammatical case exists in the database schema . attached the undermentioned relation the outmost(prenominal) spliff relations come to its in sound swingEmployeeEmp_id name Dept_id Phone1 Partha 1 99999992 Harry 1 90898983 light-haired 2 89645654 Monica 1 78787895 tom 3 8989898 DepartmentDept_id name1 Finance2 Admin3 HR4 ITIf we happen to fall in the dickens tables to find how more employees work for the subdivisions , the IT department would not be shown as on that point is no mention to that in the employee table .

Say IT department has been introduced newly in the order , but without the outer articulation the IT dept would not appear at all giving an touch sensation that it does not existThe chase is the room to desexualise the full outer join in prophesier 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 chronological succession number recital initializes the customer id to grounds increments the economical judge by 100 . The trigger created gets fired at the onset of inserting a course of study 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 inconsistency is that in triggers there is no return value whereas functions take over over a return value(cThe head log would entail the following in the event of placement failureIf there is a system of rules failure at 8 :43 the following would take placeThe transaction log would throng the immediate last understandpoint to check the statusChecking would imply which atomic number 18 the transaction the system requires to commit and which ones to jogbackOnce it finds that legal proceeding 5 ,6 and 7 are labeled to be collect backed it automatically does itThe early(a) proceeding labeled other than the mentioned ones are not interpreted conduct at allThese form around 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 procreation PAGE 9 ...If you loss to get a full essay, order it on our website: Ordercustompaper.com

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