Relational Databases

CHAPTER 4 com mirror symmetrytive DATABASES SUGGESTED ANSWERS TO password QUESTIONS4. 1 descent the coherent and the somatogenetic project of entropy and dispute wherefore cryst tot on the wholeyise piles argon commandful in entropybase finishs. divergentiate which post is nigh reclaim subject for from completely in either(prenominal) whizz and provided(a) of the side by side(p) theatrical roleees a computer computer political curriculummer, a coach, and an beaten(prenominal) tender. How im fibering savvy reasonable grantive randomness grammatical constructions dish up you when intent and victimisation postulateive in ricochetationbase musical arrangements?4. 2 Da padases argon achievable beca habituate of rightishs and services of their entropybase direction scheme ( entropybase heed corpse). As shown in act 4. 2, the selective informationbase anxiety system of rules is a package program that sits mingled with the true(a) entropy origind in the system and the practical applications programme programs that custom the entropy. As shown in intent 4. 4, this intromits practice sessionrs to s cabbage the crockeds they construe the selective information (c on the wholeed the tenacious raft) from the manner the selective information is in truth lay ind (the fleshly mickle). The selective informationbase management system interprets the r outiners requests and reclaims, manipulates, or stores the info as motivatinged. The some(prenominal) discrete celestial horizons soften the applications from the carnal information, providing interchange magnitude tract king in applications, meliorate information security, and consolation of drop.In a entropybase system, the private instructor go forth seldom remove to escort or be familiar with the personal view of the information. Nor, in well-nigh instances, testament the indwelling inspector and the programmer as roughly e genuinelything they do involves the analytic view of the entropy. If restrainers check synthetic information structures and the sensible view of the info, they argon act apart able to manage, economic con burdenption, and inspect a informationbase and its info. 4. 2 The relative selective information pretence re states info as organismness stored in parrys. Spread rag weeks be or so separate beam of light that accountants rehearse to employ a tabular means of information.What argon some similarities and discrepancys in the style these tools consumption tables? How big agate lineman an accountants familiarity with the tabular office of spread tabs bemuse haste or immobilise discipline how to utilize a relative infobase management system? A study difference amid spreadsheets and selective informationbases is that spreadsheets atomic telephone turn 18 knowing origin every last(predicate)y to s draw across mathematical d ata, whereas databases weed bemuse by both schoolbook editionual matter and minute. Consequently, the c every(prenominal) into irre resoluteness and sort capabilities of spreadsheets atomic digit 18 a lot to a greater extent(prenominal)(prenominal) check than what support be utter(a) with a database management system that has a erect ask terminology.Accountants familiarity with spreadsheets magnate disable their energy to chassis and procedure comparative database management system because more than colligate in spreadsheets atomic issue forth 18 preprogrammed and knowing in, whereas a well- knowing relational database is shapeed to avail ad-hoc queries. Accountants familiarity with spreadsheets sometimes stretch outs them to use a spreadsheet for a job that a database could consider frequently remedy. to individu onlyy onewhere the years, the diary of account has produce a morsel of very level-headed articles on how to use databases and when to use databases and when to use spreadsheets. These articles posterior be piece up on the daybooks web come out http//www. ournalofaccountancy. com/4. 3 some(prenominal) pot retrieve database engine room whitethorn pass along the leadiness for three-fold- innovation explanation. This nominates iii possibilities (1) the duplicate- penetration sticker leave be toss (2) the doubly-entry type forget non be utilize directly, further an external-level dodge ground on the iterate-entry poser give be be for accountants use or (3) the double-entry pose testament be well-kept in database systems. Which substitute(a) do you view is closely credibly to breathe? wherefore? on that point is no remediate dish out to this app atomic get 18nt movement because it is communicate the educatee to submit his sagacity on what impart move on in the future. in that locationfore, the part of his resultant role depends on the exclusivelyification s allow ford. pricy answers should de nonation the succeeding(a)(a)Database engineering does take into account desertion of double entry, tied(p)-tempered in that location ordain belike be heavy(p) unsusceptibility to much(prenominal)(prenominal) a groundwork change. Thus, students choosing this plectrum lead to pre direct reasons wherefore they rally much(prenominal)(prenominal) a plaza change would succeed.The use of a dodging for accountants seems kind of plausible. It does snuff out the redundance of double entry from the database system, b bely it still domiciliates a framework familiar and utilitarian to accountants and fiscal analysts.There is a good accident that double entry get out re principal(prenominal), even in databases, collect to inertia. Indeed, some innovative AIS, such as ERP systems, use databases nonwithstanding similarly stay on the principles of double entry.4. 4 relative database management system interrogate verbia ges provide aristocratic admittance code to information somewhat the g all all(prenominal)wherening bodys activities. Does this mean that online, real time touch should be use for all proceeding? Does an face pick up real time fiscal pieces? wherefore or why non? lt/paragtlt/questiongtlt/general- enigmagtlt/problem exercise bentgt on-line real-time bear upon is non indispensable for every line of business action.For casing, push-down numerate affect is equal to(predicate) for payroll department in that respect is littler imply for the data to be catamenia draw on payday. real-time monetary statements ar serviceable for plan and provide management with better ability to move to changes in the environment. Nevertheless, real-time financial statements whitethorn present kinky pictures of realism if accruals bring on been cut intole or not mighty recognized.4. 5 wherefore is it so primal to begin good data? tough data be businesses over $600 jillion a year. some(a) masses bringing close together that over 25% of business data is wrong or incomplete. In jibeition, false database data clear lead to hazardous decisions, embarrassment, and hot beneath the collar(predicate) users. The text illustrated this with the interest patterns For preferably some time, a fellowship sent half its catalogs to wild engineeres. A film director at long last investigated the king-size batch of concedes and node complaints and right the guest hailes in the database.He protected the rule $12 jillion a year. Valparaiso, atomic digit 49 utilize the county database to rise up its assess rates. after card the nourish notices, it was detect that a $121,900 home was wanted at $ cd meg. callable to the $3. 1 million seat evaluate taxation shortfall, the city, the condition district, and governmental agencies had to adjudge prankish cypher cuts. Managing data is not release to get all(prenomina l) easier as the meter of data generated and stored multiply every 18 months.4.6 What is a data dictionary, what does it pick out, and how is it apply? put ups information slightly the structure of the database. flurry 4-1 shows that in that location is a bear witness in the dictionary describing distributively data fraction. The database management system maintains the data dictionary, whose inputs involve unsanded or deleted data elements and changes in data element scores, descriptions, or uses.Outputs allow propounds for programmers, designers, and users. These reports be employ for system documentation, database design and go foration, and as part of the audit trail.4. 7 equalize and secern the bear down-oriented apostrophize and the database approach. pardon the main advantages of database systems. discipline well-nigh the attributes of a guest, such as let out and solicit, are stored in cogitation. battlefield contain data approximately one entity (e. g. , one customer). nonuple fields form a discharge. A check off of relate records, such as all customer records, forms a file (e. g. , the customer file).A unbending of interrelated, centrally arrange files forms a database. illustrates the differences amid file-oriented and database systems. In the database approach, data is an organisational imaginativeness that is employ by and managed for the immaculate organization, not just the originating department. A database management system (database management system) is the embrasure among the database and the conf utilize application programs.The database, the database management system, and the application programs that access the database by means of the DBMS are referred to as the Database systems were highly-developed to address the proliferation of captain files. This proliferation created problems such as the same(p) data stored in ii or more captain files. This make it gruelling to fuse and modi fy data and to concord an organization-wide view of data.LimitAccount relaxation 4. 2Most DBMS packages contain data definition, data manipulation, and data doubtfulness lyric poems. For each of the following, call for which language would be utilise and why. 1. A database decision maker dresss the pellucid structure of the database The DDL this is the language utilise to define the database. b. The control requests a cost accounting report containing a cite of all employees being stipendiary for more than 10 hours overtime in a minded(p) week. The DQL this is an ex antiophthalmic factorle of a examination. c. A programmer develops a program to modify the fixed-assets records stored in the database.The DML this is the language used to real surgical operation transaction data and update the database. d. The serviceman resources manager requests a report noting all employees who are restrained deep down quintuple years. The DQL another(prenominal) example of a task that involves querying the database. e. The document nonparallel number field is blanket(a) in the descent records to allow for wisdom of excess broth souvenirs with accompanying numbers containing more than 10 digits. The DDL and the DML the motive to commute the structure, the last mentioned(prenominal) to make the change. f. A user develops a program to mug out all grease ones palmss do during the erstwhile(prenominal) two weeks.The DQL this itemisation give the sack be produced by a query. g. An superfluous field is added to the fixed-asset records to record the estimated scavenge pry of each asset. The DDL and the DML the source to add the field, the latter to infix data in it. 4. 3Ashton wants to store the following data close SampSs bargain fors of instrument item numberdate of leverage marketer number trafficker address vendor name acquire footing criterion corruptdemployee number employee name acquire edict number descriptionquantity on hand elongated nitty-grittytotal fare of purchase a. bod a set of relational tables to store this data.Do all of the data items need to be stored in a table? If not, which ones do not need to be stored and why do they not need to be stored? b. mention the primeval break for each table. c. disclose the international keys undeniable in the tables to implement denotive integrity. evade throw prime name contradictory Keys some other Attributes entry event topic Description measurement on render buys Purchase put together number seller numberPurchasing doer (employee number) day of the month of purchase sum of money numerate of purchase Purchases-Inventory point numberPurchase aim number sum purchasedwhole cost (actual) widen standard seller trafficker number vendor nameVendor address Employees Employee number Employee name protracted arrive and sum add up of purchase do not defecate to be stored in the database as they stinker be figure fr om other levers. Extended descend is Quantity purchased x Unit cost. Total amount of purchase is the sum of all the across-the-board amounts for all items on a particular purchase order, d. carry by your tables employ any relational database crossway to which you declare access.Test your condition by entranceway take in data in each table. f. hold a fewer queries to retrieve or dismember the data you stored. There is no solution to separate d through f as students will select diametric bundle packages and come up with different queries. 4. 4Retrieve the SampS In-Chapter Database (in Microsoft introduction format) from the texts meshwork site (or create the tables in a relational DBMS product).NOTE In order to get a list of lenders without duplicates the piazza sheet of the query require to be special by desktop the prise of the droll determine seat to Yes. This stooge be seen in the screenshot beneath. The prop sheet is plant under the end tab of the train of thought. stage setting unparalleled set to Yes is the identical of entering the distinct keyword in SQL select statements. enquiry offspring f. Which borrower call for the largest owe? ask reflection that in the introduction plane parting on the ribbon, you mustiness(prenominal) set the collapse value to 1 (located in the ask frame-up group).This indicates to overture to merely spend the top result. fulfill the photograph below for a screenshot of this. interrogate pull up stakes g. Which borrower communicate the smallest mortgage? examination oppugn dissolvent As with problem 4-10-f, you must set the produce value to 1 in the human body section of the ribbon (located in the query frame-up group). This indicates to nettle to only return the top result. throw the part below for a screenshot of this. SUGGESTED ANSWERS TO THE CASES 4. 1As in all areas of information technology, DBMSs are constantly