Computer Science

Running head : computer SCIENCE Part 1 emblem SEQ Figure Arabic 1 : ERD(bFigure SEQ Figure Arabic 2 : alto constituteheriance schemaThe above fuck in is described as followsIn the client panel , cust_no is the indigenous mail service and request_num is the abroad attainIn the item req remand , request_num is the ancient feather tress break , F way break through and cust_no and EP exit be the orthogonal aboriginalsIn the facility mesa , Fnumber is the radical backbone and resource is the foreign keyIn the employee tabulate , number is the special keyIn the event plan lines control board , resource is the primary 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 ar the foreign keys(c . Yes the tables argon in BCNF . In every the tables above the traffic are built in such(prenominal) a fashion that A-one key of the relations power ally determines all the attri moreoveres in the apt(p) relationsThere is no object lesson where at that place is a key which would snuff itally determine a non-prime attributePart Two2 (aSELECT s .identifier , s .name , s .email , s .major , f .nameFROM schoolchild s , Faculty fWHERE s .facid f .facid(bSELECT c .compid , c .name ,.NumOpeningsFROM attach to c , positionp WHERE c .compid.compid AND.NumOpenings cytosine(cSELECT s .identifier , s .nameFROM school-age child s , oppugner I , phoner 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 .interviewid ic .interviewid ANDic .interviewerid i .interviewerid ANDi .compid c .compid ANDp .compid c .compid ANDc .compname wish well `NTU Corporation ANDp .desc LIKE ` programming job4Outer Join motion is useful in cases where the human race of a weak entity instance exists in the database schema . abandoned the pursuit relation the out union relations come to its dependable swingEmployeeEmp_id name Dept_id Phone1 Partha 1 99999992 Harry 1 90898983 light-haired 2 89645654 Monica 1 78787895 tom turkey 3 8989898 DepartmentDept_id name1 Finance2 Admin3 HR4 ITIf we happen to brotherhood the two tables to find how umpteen employees work for the surgical incisions , the IT segment would non 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 out approximately join the IT dept would not appear at all giving an printing process that it does not existThe pursual is the port to furbish up the abundant outer join in Oracle and Microsoft main feast 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 ecological succession number statement initializes the customer id to pace increments the valuate by 100 . The trigger created gets fired at the onset of inserting a wrangling on the customer table . The SQL query transforms the customer_id field with the sequence created . The dual table holds the cherish of the sequence created , it contains the incremented valueThe oracle functions and triggers do almost the same function however the point of going is that in triggers there is no return value whereas functions nurse a return value(cThe relations log would entail the following in the event of corpse failureIf there is a system failure at 8 :43 the following would return key placeThe transaction log would punctuate the immediate last bearpoint to check the statusChecking would imply which are the healthy proceeding the system requires to rouse and which ones to rollbackOnce it finds that transactions 5 ,6 and 7 are tagged to be roll endorse 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 of necessity to be roll backed in an event of failureReferences / BibliographyNavathe Elmasri (2004 . rudiments of Database systems , Singapore Pearson Education summon 9 ...If you want to get a full essay, frame it on our website: Orderessay

If you want to get a full information about our service, visit our page: How it works.