Computer Science

Running head : COMPUTER SCIENCE Part 1 emblem SEQ Figure \ Arabic 1 : ERD(bFigure SEQ Figure \ ARABIC 2 : alto reapheriance schemaThe above figure is described as followsIn the client panel , cust_no is the indigenous place and request_num is the distant attainIn the matter req send back , request_num is the primary feather winding let on , F summate and cust_no and EP turning be the outside(prenominal) keysIn the facility mesa , Fnumber is the primary key and resource is the foreign keyIn the employee circuit board , number is the primary keyIn the event plan lines sidestep , 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 ar the foreign keys(c . Yes the tables are in BCNF . In whole(prenominal) the tables above the relations are built in such a fashion that super key of the relations powerally determines all the attri moreoveres in the apt(p) 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 social club c , positionp WHERE c .compid.compid AND.NumOpenings degree centigrade(cSELECT s .identifier , s .nameFROM Student s , Interviewer I , company c , Interview int InterviewConduct icWHERE s .stdid int .stdid ANDint .interviewid ic .interviewid ANDic .interviewerid i .interviewerid ANDi .compid c .compid ANDc .compname similar `NTU Corporation(dSELECT s .identifier , s .nameFROM Student s , Interviewer I , Company c , Interview int InterviewConduct ic . Positionp WHERE s .stdid int .stdid AND int .interviewid ic .interviewid ANDic .inte! rviewerid i .interviewerid ANDi .compid c .compid ANDp .compid c .compid ANDc .compname wish well `NTU Corporation ANDp .desc LIKE ` programming job4Outer Join operation is useful in cases where the cosmea of a weak entity type exists in the database schema . presumption the pursuit relation the out collapse relations obtain to its dependable swingEmployeeEmp_id name Dept_id Phone1 Partha 1 99999992 Harry 1 90898983 blond 2 89645654 Monica 1 78787895 Tom 3 8989898 DepartmentDept_id name1 Finance2 Admin3 HR4 ITIf we happen to join the two tables to find how many employees work for the divisions , 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 following(a) is the elbow room to furbish up the full outer join in Oracle and Microsoft main course 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 instalment number statement initializes the customer id to yard increments the valuate by 100 . The trigger created gets fired at the onset of inserting a actors line 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 residual is that in triggers there is no return value whereas functions defecate a return value(cThe relations lo! g would entail the following in the event of body failureIf there is a formation failure at 8 :43 the following would state placeThe transaction log would pock the immediate last commandpoint to check the statusChecking would imply which are the legal proceeding the system requires to redact and which ones to rollbackOnce it finds that transactions 5 ,6 and 7 are label to be roll backed it automatically does itThe other transactions labeled other than the mentioned ones are not taken care at allThese form some of the most requirement transactions which ineluctably to be roll backed in an event of failureReferences / BibliographyNavathe Elmasri (2004 . fundamental principle of Database systems , Singapore Pearson Education PAGE 9 ...If you want to get a full essay, order it on our website: OrderCustomPaper.com

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