________ database specification shows all the parameters for information storage that are theninput to database implementation.A) LogicalB) PhysicalC) SchematicD) Conceptual
A create of database specification which maps conceptual requirements is called:A) logical specifications.B) response specifications.C) protection specifications.D) physical specifications
A two-dimensional table of information sometimes is called a:A) team.B) set.C) declaration.D) relation.
You are watching: A candidate key must satisfy all of the following conditions except:
________ is a component of the relational information model included to specify company rules topreserve the integrity of information when they are manipulated.A) Business dominance constraintB) Data integrityC) Company integrityD) Documents structure
An attribute (or attributes) that uniquely identifies each row in a relation is dubbed a:A) column.B) foreign field.C) primary crucial.D) duplicate vital.
An attribute in a relation of a database that serves as the primary crucial of another relation in theexact same database is referred to as a:A) attach attribute.B) attach essential.C) international key.D) foreign attribute.
A major essential whose value is distinct across all connections is dubbed a(n):A) international main key.B) inter-table major crucial.C) enterpincrease vital.D) foreign international key
A major essential that is composed of MORE THAN ONE ATTRIBUTE IS CALLED A:A) foreign key.B) composite vital.C) multivalued essential.D) cardinal crucial.
In the SQL language, the ________ statement is offered to make table definitions.A) produce sessionB) produce tableC) create indexD) select
In the number below, the main crucial for "Order Line" is which kind of key?A) CompositeB) ForeignC) StandardD) Grouped
A domajor meaning is composed of every one of the complying with components EXCEPT:A) domajor name.B) data kind.C) integrity constraints.D) dimension.
No 2 rows in a relation are identical.
Which of the complying with are properties of relations?A) Each attribute has actually the same name.B) No two rows in a relation are similar.C) Tbelow are multivalued features in a relation.D) All columns are numeric
Which of the complying with violates the atomic home of relations?A) SamB) HinzC) Sam HinzD) Atomic
no main key attribute have the right to be null.
The entity integrity ascendancy claims that:A) no primary vital attribute can be null.B) referential integrity need to be preserved across all entities.C) each entity have to have a major key.D) a primary essential have to have only one attribute
entity integrity ascendancy
The ________ says that no primary essential attribute may be null.A) referential integrity constraintB) entity integrity ruleC) partial specialization ruleD) variety domain rule
In the number listed below, Customer_ID in the CUSTOMER Table is which kind of key?A) CompositeB) CandidateC) StandardD) Grouped
Maximize Storage Pace
All of the following are the primary objectives of normalization EXCEPT:A) minimize information redundancy.B) simplify the enforcement of referential integrity.C) maximize storage room.D) make it less complicated to keep data
First normal develop
When all multivalued qualities have been removed from a relation, it is shelp to be in:A) initially normal create.B) second normal develop.C) Boyce-Codd normal form.D) third normal form
Boyce-Codd normal develop.
The normal develop which gets rid of any staying sensible dependencies bereason there waseven more than one major crucial for the exact same nonkeys is called:A) fifth normal develop.B) fourth normal form.C) Boyce-Codd normal develop.D) sixth normal develop.
fourth normal develop.
The normal form which deals with multivalued dependencies is called:A) fifth normal create.B) fourth normal create.C) Boyce-Codd normal create.D) 6th normal form.
A relation that consists of no multivalued characteristics and has nonessential attributes solely dependenton the primary crucial however contains transitive dependencies is in which normal form?A) FirstB) SecondC) ThirdD) Fourth
A constraint in between 2 qualities is referred to as a(n):A) practical relation.B) attribute dependency.C) practical dependency.D) practical relation constraint
the vital need to show the row's position in the table
A candidate essential should accomplish all of the adhering to problems EXCEPT:A) the vital need to uniquely recognize the row.B) the key must indicate the row's place in the table.C) the crucial need to be nonredundant.D) each nonessential attribute is functionally dependent upon it.
The attribute on the left-hand also side of the arrow in a useful dependency is the:A) candiday key.B) determinant.C) foreign key.D) main essential.
A practical dependency in which one or more nonessential qualities are functionally dependenton part, but not all, of the primary key is called a ________ dependency.A) partial key-basedB) partial functionalC) cross keyD) unified relation
A practical dependency in between two or even more nonkey attributes is dubbed a:A) partial useful dependency.B) partial nonvital dependency.C) transitive dependency.D) partial transitive dependency.
________ difficulties are encountered as soon as removing data through transitive dependencies.A) InsertionB) ModificationC) DeletionD) Merging
The should ________ connections frequently occurs when various views should beincluded.A) metadataB) systemC) dropD) merge
Two or even more characteristics having actually different names however the very same interpretation are called:A) homonyms.B) aliases.C) synonyms.D) alternate features.
An attribute that might have actually more than one meaning is called a(n):A) homonym.B) alias.C) double identified attribute.D) synonym.
An different name for an attribute is dubbed a(n):A) synonym.B) alias.C) alternative attribute.D) connected characteristic
one need to be able to inspect the output of a CASE tool.
Understanding the measures connected in transforming EER diagrams into connections is importantbecause:A) one need to have the ability to inspect the output of a CASE tool.B) tright here are hardly ever legitimate alternatives from which to pick.C) CASE devices deserve to model any kind of instance.D) CASE tools design theoretical organization problems
A nonkey attribute is also called a(n):A) column.B) unimportant datum.C) descriptor.D) address.
develop two new connections, one containing the multivalued attribute.
When a regular entity type includes a multivalued attribute, one must:A) create a solitary relation via multiple lines for each circumstances of the multivalued attribute.B) create 2 brand-new connections, one containing the multivalued attribute.C) develop 2 new relationships, both containing the multivalued attribute.D) delete the relation and start over.
Strong entity/weak entity
In the figure below, what type of relationship execute the relations depict?A) Strong entity/weak entityB) MultivaluedC) Compowebsite international keyD) One-to-many
In the figure listed below, what form of connection do the relations depict?A) Strong entity/weak entityB) One-to-manyC) TernaryD) Many-to-many
An associative entity
In the number below, what is depicted?A) A one-to-one relationshipB) A unary relationshipC) A one-to-many relationshipD) An associative entity
In the figure listed below, what form of essential is depicted?A) PrimaryB) Recursive primaryC) CompositeD) Recursive foreign
A component is constantly provided in only one item.
Referring to the figure listed below, which of the following is NOT true?A) A component is part of an item.B) A component is always provided in just one item.C) A component have the right to be component of an object.D) A component might be used in many type of items
The figure below is an example of mapping which type of relationship?A) FirstB) SecondC) UnaryD) Ternary
________ are anomalies that deserve to be caused by editing data in tables.A) InsertionB) DeletionC) ModificationD) Creation
A relation that contains minimal redundancy and allows straightforward usage is thought about to be:A) clean.B) easy.C) complicated.D) well-structured
referential integrity constraint.
A dominion that claims that each foreign crucial worth have to enhance a major vital worth in the otherrelation is dubbed the:A) referential integrity constraint.B) crucial complement dominance.C) entity vital team preeminence.D) foreign/primary complement rule.
A major vital uniquely identifies each row of a relation (or table). It can be either asingle column or a composite of two or even more columns, which is referred to as a composite essential. Ainternational vital enables us to recurrent the connection between two tables. A foreign key in one tableis mostly a reference to a main vital in another table
Discuss the various relational secrets.
Each relation (or table) has actually a distinct name. An enattempt at the intersection of each row andcolumn is atomic and also each row is unique. Each attribute (or column) within a table has actually a uniquename. The sequence of rows and columns is inconsiderable
Discuss the properties of relations
A multivalued attribute is one that can take on even more than one worth. According to theinterpretation of a relation, tright here have the right to be no multivalued features. The factor for this will certainly be seenlater once the schema is normalized. A multivalued attribute have the right to be reresolved by producing aseparate circumstances for each worth and repeating the data from the non-multivalued features
Discuss why it is necessary to remove multivalued qualities from a relation
A candiday key is an attribute or a combination of characteristics that uniquely identifies arow in a relation. A candiday vital should be nonredundant and have to also uniquely identify eachrow. When we look at sensible dependencies and also candiday tricks, we can constantly say that adeterminant is constantly a candidate key.
Exsimple what a candiday essential is and also exactly how it could be used
Each constant entity is transdeveloped into a relation. Tright here are a couple of things that needto be done through some one-of-a-kind types of attributes. Compowebsite qualities are broken down right into theirindividual components. Multivalued qualities are broken dvery own into sepaprice connections. Forinstance, if there was a multivalued skill attribute, this would come to be a ability relation. Also, weoverlook acquired qualities.
Discuss how you would map a regular entity to a relation.
A weak entity becomes a relation. However before, because a weak entity instance does not existby itself, we need to develop a relation via the primary key from the solid relation as the primarycrucial, and the identifying attribute.
How perform you convert weak entities to relations?
A surrogate key should be developed once any type of of the adhering to conditions hold: tright here is acomposite primary key, the herbal main key is inreliable (such as a long name) or the naturalprimary essential is recycled. When you have actually an associative entity, it is regularly finest to use a surrogatecrucial as soon as you have more than two relationships that the associative entity is pertained to, because themain vital would certainly be a composite of the primary tricks of all entities related to the associativeentity.
Discuss as soon as it is finest to develop a surrogate essential for an associative entity
Tright here are two feasible instances for associative entities. In one situation, you deserve to have anidentifier assigned. You would then use this as the primary vital. The various other instance is wbelow theidentifier is not assigned. In this case, you would certainly use the major tricks from the various other two (ormore) connections that are pertained to the associative entity.
Discuss the two feasible scenarios when mapping an associative entity
The entity form in the unary relationship is mapped to a relation in the very same way as wedid for a relation. We next include a international crucial attribute, which maps back to the major key. Thisis referred to as a recursive foreign vital. So, if we had actually a relation such as a perkid supervises one or morepersons, the person_id would certainly be a main vital and then tright here would be a supervisor id whichpoints ago to the person_id
Discuss how to map a unary one-to-many connection.
Two relationships are developed. One represents the entity type in the relationship, and also theother is an associative relation to reexisting the M:N connection. The primary essential of theassociative relation is composed of two characteristics which take their value from the major vital of theother relation.
Discuss how to map a unary many-to-many relationship.
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When we have actually a supertype/subtype connection, we must asauthorize one entity for thesuperkind and one for each subform. The supertype has actually all features common to all subforms aswell as a major vital. Each subform relation has actually the primary essential of the superkind and anycharacteristics that are particular to that subtype. Finally, we assign one or more features to thesupertype to function as subkind discriminators
Explain exactly how subtype/supertype relationships are converted to relations
The three major kinds of integrity constraints are doprimary constraints, entity integrityand referential integrity. A domain is a collection of characteristics assigned to an attribute and is composed ofthe doprimary name, data kind, dimension and also allowable values. The entity integrity ascendancy is designed toensure that eincredibly relation has actually a primary crucial and also that the data worths for the primary crucial are valid(in certain, not null). The referential integrity constraint is a preeminence that maintains consistencyamong the rows of 2 relations. If tright here is a international essential in one relation, tbelow need to be aequivalent major essential in the other relation or the foreign key need to be null
Discuss the types of integrity constraints.
An anomaly is an error or inconsistency that might result when a user attempts to updatea table that has redundant data. Tright here are three forms of anomalies. An insert anomalyoccurs as soon as a user attempts to enter new information for part of a table. For instance, if westored customer deal with with an order. A deletion anomaly occurs when the user wants to deletepart of a record however likewise has to delete related information. A alteration anomaly occurs when we haveto change the same data in multiple areas
What is an anomaly, and what are the three forms of anomalies?
During logical database style, normalization is supplied as a check and balance to makecertain that your E-R diagram is correct and your relational schema prior to doing physicalarchitecture. Another occasion once you benefit is reverse-engineering an older device, given that manyof the tables and also user views are redundant.
Discuss the two significant occasions as soon as you advantage from utilizing normalization
Tbelow are 6 different normal creates, all of which build upon each other. When arelation is in initially normal create, all repeating groups have actually been removed. 2nd normal formimplies that any type of partial useful dependencies have actually been rerelocated. A partial functionaldependency occurs once a major crucial is a composite crucial and a nonvital attribute is dependentupon part of the crucial. A relation is in 3rd normal develop when all transitive dependencies havebeen reresolved. A transitive dependency occurs when one noncrucial attribute is dependent uponone more noncrucial attribute. Boyce-Codd normal develop clears any type of further dependencies that mayresult from anomalies. A relation is in fourth normal create when any dependencies frommultivalued characteristics have actually been rerelocated. Fifth normal form removes any further anomalies.LO: 4.8: Use normalization to decompose a relation through anomalies right into well-structured
List and also describe first, 2nd, 3rd, BCNF, fourth, and fifth normal forms