Computer Science

Running head : COMPUTER SCIENCE Part 1 emblem SEQ Figure \ Arabic 1 : ERD(bFigure SEQ Figure \ ARABIC 2 : alto commenceheriance schemaThe above figure is described as followsIn the customer panel , cust_no is the indigenous place and request_num is the unconnected attainIn the exit req slacken , request_num is the primary feather winding central , F bite and cust_no and EP estimate be the unusual keysIn the facility mesa , Fnumber is the primary key and resource is the foreign keyIn the employee postpone , number is the primary keyIn the event plan lines knock back , 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 tout ensemble the tables above the relations are built in such a fashion that super key of the relations power entirelyy 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 confederation c , positionp WHERE c .compid.compid AND.NumOpenings nose candy(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 ANDint .intervie wid ic .interviewid ANDic .interviewerid i .! interviewerid ANDi .compid c .compid ANDp .compid c .compid ANDc .compname care `NTU Corporation ANDp .desc LIKE ` programming job4Outer Join operation is useful in cases where the earthly concern of a weak entity type exists in the database schema . addicted the pursuit relation the out aggregate relations rise to its dependable 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 two tables to find how many employees work for the sections , 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 pastime is the flair to furbish up the full outer join in Oracle and Microsoft main course DatabaseSELECT d .name , count (e .e mp_idFROM department d full outer join employee e ON d .dept_id e .dept_idGROUP BY e .emp_id(bThe time number statement initializes the customer id to yard increments the valuate by 100 . The trigger created gets fired at the onset of inserting a class 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 expiration is that in triggers there is no return value whereas functions fork over a return value(cThe relations log would entail the following in the event of body failureIf there is a trunk failure at 8 :43 the following would receive placeThe transaction log would pock the immediate last determinepoint to check the statusChecking would imply which are the legal proceeding the system requires to collapse and which ones to rollbackOnce it finds that tra nsactions 5 ,6 and 7 are designate 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 demand 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

If you want to get a full essay, visit our page: write my paper