Section 8 Quiz (Answer all questions in this section) 1. You You are doing a data model for a computer sales company where the price fluct
A. %reate a product entity and a related price entit '. %reate a new item aand nd a new price e&ery e&er y day. %. se a price entity with a start and end date . Allow them to delete the item and enter a new *. 'oth A and % (+) %orrect ,. -hat is the function of logging or ournaling in conceptual data models$
Allows you to trac" the history of attriute &alues# 0i&es a timestamp to all entities. %reates a fied time for all e&ents in a data model. 2epresents entities as time in the data model. %orrect 3. You You are doing a data model for a computer sales company where the price of po
Allow them to enter whate&er deli&ery charge the pdate the prices in the system# print out the curre *mail current prices to all employees whene&er a se a eli&ery ay entity# which holds prices agai %orrect 5. 6istorical data must ne&er e "ept. 7rue 7rue or alse$
7rue
alse (+) %orrect 9. -hich of the following scenarios should e modeled so that historical data is "e
(%hoose all correct answers) S7*:7 and A0* ;!'2A2Y and :<'*2 4 '44=S ;!'2A2Y and '44= (+) S7*:7 and 02A* (+) %orrect >age 1 of 3
Section 8 Quiz (Answer all questions in this section) ?. 6istorical data should always e "ept. 7rue or alse$
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7rue alse (+) %orrect @. -hich of the following would e a logical constraint when modeling time for a %ity entity$
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>eople are orn in the city and people die in the city. %ites may change their names and/or country association if the orders of a country change. (+) aily traffic patterns must e monitored to determine how many law enforcement officers are needed.
!f you are doing a system for any rench %ity# you would need security clearance. %orrect 8. -hen a relationship may or may not e transferale# depending on time# this is "now as a/an
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7ransferale 2elationship %onditional :onBtransferale 2elationship. (+) :onBtransferale 2elationship. Arc. %orrect C. !n a payroll system# it is desirale to ha&e a n entity called AY with a holiday attriute when you want to trac" special holiday dates. 7rue or alse$
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7rue (+) alse %orrect 1D.7here are no circumstances where you would create a AY entity. 7rue or alse$
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7rue alse (+) !ncorrect. 2efer to Section 8 ;esson ,.
>age , of 3
Section 8 Quiz (Answer all questions in this section)
11.-hich of the following would e a logical constraint when modeling time for a country entity$
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!f you are doing a system for rance or 0ermany# you would need security clearance. %ountries may change their names and/or orders o&er a period of time. (+) aily traffic patterns must e monitored to determine which countries are o&ercrowded. >eople ha&e irths and deaths dea ths in their countries that must e trac"ed y the system. %orrect 1,.7here is no point in trying to group your entities together on your diagram according to &olume# and ma"ing a diagram loo" nice is a waste of time. 7rue or alse$
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7rue alse (+) %orrect 13.ormal rules eist for drawing *2Es. You You must always follow them# e&en if it results in an *2 that is difficult d ifficult to read. 7rue 7rue or alse$
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7rue alse (+) %orrect 15.-hich of the following statements are true to enhance the readaility of *2s$ (%hoose 7wo) 7wo)
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(%hoose all correct answers) %rows feet (the manyBends of relationships) should consistently point the same direction where possile# either South F *ast or :orth F -est -est (+) %rossing relationship lines help the readaility of the diagram. !t does not matter which way the crows feet (many ends of a relationship) point.
2elationship lines should not cross. (+) %orrect 19.!n an *2# 6igh Golume Golume *ntities usually ha&e &ery few relationships to other entities. 7rue or alse$
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7rue alse (+) %orrect
>age 3 of 3
Section C Quiz (Answer all questions in this section) 1.-hy would this tale name :47 wor" in an 4racle dataase$ thisHyearHendInetHyear
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7ale 7ale names must egin with an alphaetic character. !t is too long. 7he >lus sign I is not allowed in oect names. (+) :one of the ao&e. %orrect ,.Attriutes ecome columns in a dataase tale. 7rue or alse$
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7rue (+) alse %orrect 3.!n an 4racle dataase# why wh y would 1H7A';* 1H7A';* not wor" as a tale name$
(1) >oints 7he dataase does not understand un derstand all capital letters. 7here is no prolem here. You You can create a tale called 1H7A';*. 7A';* 7A';* is a reser&ed word. 4ect names must not start with a numer. 7hey must egin with a letter. (+) %orrect 5.!n an 4racle dataase# why would the following tale name not e allowed E*<>;4Y** J4'SE$
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*<>;4Y** is a reser&ed word J4'S is a reser&ed word You You cannot ha&e spaces etween words in a tale name (+) 7he dataase does not understand un derstand all capital letters %orrect 9.-hen translating an arc relationship to a ph ysical design# you must turn the arc relationships into foreign "eys. -hat additional step must you ta"e with the created foreign "eys to ensure the eclusi&ity principle of arc relationships$ (Assume that you you are implementing an *clusi&e esign) (%hoose 7wo) (%hoose all correct answers) age 1 of 3
Section C Quiz
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(Answer all questions in this section) ?. -hich of the following is a &alid reason for considering a Sutype !mplementation$
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7he resulting tale will reside in a single dataase a nd e used y ust 4:* user. 7he common access paths for the supertypes are different. 'usiness functionality# usiness usiness rules# access paths# and frequency of access are all &ery &er y different etween the sutypes. (+)
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7rue alse (+) %orrect 8. oreign "eys cannot e null when
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!t is part of a primary "ey (+) !t contains three or more columns !t refers to another tale !t refers to the same tale %orrect C. %olumn integrity refers to
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%olumns always containing &alues consistent with the defined data format (+) %olumns always containing tet data less than ,99 characters %olumns always ha&ing &alues
%olumns always containing positi&e numers %orrect 1D.7he eplanation elow is an eample of which constraint type$ !f the &alue in the alance column of the A%%4:7S tale is elow 1DD# we must send a letter to the account owner which will require etra programming to enforce.
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serBdefined integrity (+) 2eferential integrity %olumn integrity *ntity integrity %orrect
>age , of 3
Section C Quiz (Answer all questions in this section) 11.A foreign "ey cannot refer to a primary "ey in the same tale. 7rue or alse$
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7rue alse (+) %orrect 1,.An Arc is transformed to the physical model y adding a foeign =ey for e&ery relationship in the Arc. 7rue 7rue or alse$
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7rue (+) alse !ncorrect. 2efer to Section C ;esson 3.
13.!n a physical model# many to many relationships are resol&ed &ia a structure called a(n) HHHHHHHHHHHHHHHH
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Sutype !ntersection *ntity (+) Supertype !ntersection 7ale %orrect 15.7o resol&e resol&e a many to many man y relationship in a physical model you create a(n) HHHHHHHHHHHHHHHHHHH$
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!ntersection tale (+) !ntersection entity nique "ey constraints 7wo 7wo tales with oreign "ey constraints etween them %orrect 19.2elationships on an *2 can only e transformed into !s in the physical model$ 7rue 7rue or alse$
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7rue alse (+) %orrect
>age 3 of 3
