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DBMS
Database test 1
113
Computer Networking
Undergraduate 4
10/03/2015

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Term
Data
Definition
Numerical or other information represented in a form suitable for processing by computer.
Term
information
Definition
A collection of facts
Term
knowledge
Definition
Term
Data as a corporate resource
Definition
Used to hold such items as capital, inventory,personnel, and patents. Suggested that data is the most important corp. resource because it describes all of the others. important to keep track, protect, and distribute it.
Term
Problems and issues in storing data
Definition
Term
How the DBMS works
Definition
Term
Desktop vs. Enterprise DBMSs
Definition
Term
Attribute
Definition
is a property of, or characteristic of, or fact about an entity
Term
Entity integrity
Definition
Term
primary keys
Definition
Term
Referential integrity
Definition
Term
foreign keys
Definition
Term
candidate Key
Definition
Term
surrogate key
Definition
Term
Resolving M:N relationships
Definition
To resolve this ___ relationship, you can add an intersect entity
Term
Unary - Self referencing
Definition
associate occurrences of an entity type with other occurrences of the SAME entity type.
Term
Binary relationship is a relationship between two __________
Definition
entity types
Term
A university wants to keep track of which professor taught which subject to which student. This is a _____ relationship.
Definition
ternary
Term
Existence Dependency
Definition
Whenever the existence of an entity depends on the existence of another entity, that relationship is described as an existence dependency (ED).
For example, suppose there are two entities named Author and Book. A writer might have been provided with an advance to write a book for a publisher, but if this is the first book written by the writer for this publisher, there will be no entry in the Book entity until the contracted book has been written and published. In this case, the relationship between Author and Book is 1:0, indicating that the existence of an instance of Book is optional.
Term
Identification Dependency
Definition
Term
Entity Relationship Diagrams (ERDs)
Definition
a diagramming technique that describes entities, their attributes, and the relationships between them
Term
When data structures can be modified without affecting the programs that use the data, we say that the environment is highly _____.
Definition
data independent
Term
Data integrity problems result from the incorrect updating of redundant data
Definition
True
Term
A file is a collection of records of the same structure.
Definition
True
Term
The database concept
Definition
Term
Data storage problems
Definition
1. Establishing relationships
2. Removing redundancy
3. Control of data
Term
Security
Definition
has become a very broad topic, including protecting the physical hardware, defending against hacker attacks, encrypting data transmitted over networks and educating employees on the importance of protecting the companies data.
Term
Associations between entity is a
Definition
relationship
Term
A binary relationship is a relationship between two ____
Definition
two entity types
Term
The term “binary” in binary relationship indicates that the relationship is between
Definition
two entity types
Term
The cardinality of a relationship is _____.
Definition
The maximum number of entities that can be involved in the relationship.
Term
The modality of a relationship is _____.
Definition
The minimum number of entities that can be involved in the relationship.
Term
A one-to-one binary relationship _____.
Definition
involves two entity types
Term
A one-to-many binary relationship allows an occurrence of the entity type on the ““one side” of the relationship to be associated with _____.
Definition
multiple occurrences of the entity type on the “many side” of the relationship
Term
A many-to-many binary relationship allows an occurrence of one entity type to be associated with _____.
Definition
multiple occurrences of another entity type
Term
Abusiness school’s faculty parking lot has assigned parking spaces. Each professor is entitled to one parking space. This is an example of a _____ relationship.
Definition
one-to-one binary
Term
Each building on a university campus has several faculty offices. Each professor has one office. The relationship between campus buildings and professors is a _____ relationship
Definition
one-to-many binary
Term
A ternary relationship allows an occurrence of one entity type to be associated with _____.
Definition
multiple occurrences of two other entity types
Term
A one-to-one unary relationship involves a single entity type
Definition
True
Term
A one-to-one unary relationship associates one occurrence of an entity type with one occurrence of another entity type.
Definition
False
Term
Strong entity
Definition
has its own PK, represented by a rectangle, PK is on of its attributes which uniquely id's its members
Term
Weak Entity
Definition
it does not save suffiecient attributes to form a PK on its own, it is represented by double rectangle, contains a partial key or discriminator represented by a dashed underline
Term
Data attributes describe
Definition
describing entities, and the relationships between the entities.
Term
Backup & recovery
Definition
having multiple copies in different physical locations to prevent a catastrophic event to from destroying all copies of the file.
Term
Concurrency control
Definition
concept that is used to address conflicts with the simultaneous accessing or altering of data that can occur with a multi-user system. Concurrency control, when applied to a DBMS, is meant to coordinate simultaneous transactions while preserving data integrity.
Term
When data structures can be modified without affecting the programs that use the data, we say that the environment is highly _____.
Definition
data independent
Term
Protecting against hackers is primarily a matter of _____.
Definition
computer security
Term
Rebuilding a database after it is destroyed by a natural disaster is an aspect of _____.
Definition
backup and recovery
Term
Problems caused by two or more users trying to update the same data simultaneously fall primarily under the heading of _____.
Definition
concurrency control
Term
Regarding the three data control issues of security, backup and recovery, and concurrency, a database management system _____.
Definition
should be responsible for handling all of them
Term
A database management system is designed to handle _____ relationships without introducing data redundancy or causing other problems.
Definition
unary, binary, and ternary
Term
By definition, a database management system _____.
Definition
permits data to be stored non-redundantly and provides for data integration
Term
When different kinds of data (data about different entities) are merged in one file, which of the following anomalies can occur?
Definition
deletion, insertion, and update
Term
All of the following are true about data redundancy across multiple files, except _____.
Definition
it speeds updates when the redundant data must be updated
Term
Which of the following does not change the contents of a file?
Definition
Retrieve
Term
Which of the following is the unique identifier of an entity?
Definition
Key
Term
Which of the following is a collection of descriptions of the entities in an entity set?
Definition
File
Term
In relational database, the basic data structure that appears to be similar to a file is called a ____.
Definition
relation
Term
A candidate key of a relation that is not chosen to be the primary key ____.
Definition
is called an alternate key
Term
Doctors and patients are in a binary one-to-many relationship as:
Doctor <--->-> Patient
To accomplish this in a relational database _____.
Definition
The primary key of the DOCTOR relation is placed as a foreign key in the PATIENT relation.
Term
An attribute(s) that acts as a foreign key in a relation ____.
Definition
may be part of the primary key of that relation
Term
Storing a binary many-to-many relationship in a relational database ____.
Definition
requires the addition of one additional relation
Term
the primary key of the relation added to accomplish the many-to-many relationship ____.
Definition
is the combination of the primary keys of the two relations involved in the many-to-many relationship plus possible additional attributes
Term
In relational database terminology, the terms column and tuple are synonymous.
Definition
False
Term
In relational database terminology, the terms row and relation are synonymous.
Definition
False
Term
A join in which one of the two identical join columns in the result is eliminated is called a(n) ____.
Definition
complex join
Term
Row definition
Definition
is a data record within a table. Each row, which represents a complete record of specific item data, holds different data within the same structure.
Term
tuple definition
Definition
a row of values in a relational database
Term
column definition
Definition
is a set of data values, all of a single type, in a table. ____define the data in a table, while rows populate data into the table.
Term
relations definition
Definition
is a predefined row/column format for storing information in a relational database. ____ are equivalent to tables.
Term
equijoin definition
Definition
is a join with a join condition containing an equality operator ( = ). An _____ combines rows that have equivalent values for the specified columns.
Term
innerjoin definition
Definition
(sometimes called a "simple join") is a join of two or more tables that returns only those rows that satisfy the join condition.
Term
natural join definition
Definition
tatement that compares the common columns of both tables with each other. One should check whether common columns exist in both tables before doing a natural join.
Term
outer join (Left)definition
Definition
returns all rows from the left table in the LEFT OUTER JOIN clause, not matter if the joined columns match. If a row in the left table (first table) doesn’t match a row in the right table (second table), the returned value for the second table is set to NULL
Term
outer join (Right)definition
Definition
returns all rows from the right table in the RIGHT OUTER JOIN clause, not matter if the joined columns match. If a row in the right table (second table) doesn’t match a row in the left table (first table), the returned value for the first table is set to NULL.
Term
outer join (full)definition
Definition
is the set of all combinations of tuples in R and S that are equal on their common attribute names, in addition to tuples in S that have no matching tuples in R and tuples in R that have no matching tuples in S in their common attribute names.
Term
A ternary relationship involves ____ entity type(s).
Definition
three
Term
Representing a ternary relationship in a relational database ____.
Definition
requires the creation of an additional relation
Term
Referential integrity is an issue in record ____.
Definition
insertion, deletion, and updating
Term
If the referential integrity delete rule between two relations is restrict, the deletion of a record in the relation on the “one side” of the one-to-many relationship may result in the deletion of one or more records in the relation on the “many side” of the relationship.
Definition
True
Term
If the referential integrity delete rule between two relations is cascade, the deletion of a record in the relation on the “one side” of the one-to-many relationship may result in the deletion of one or more records in the relation on the “many side” of the relationship.
Definition
True
Term
If the referential integrity delete rule between two relations is set-to-null, the deletion of a record in the relation on the “one side” of the one-to-many relationship may result in the deletion of one or more records in the relation on the “many side” of the relationship
Definition
False
Term
If the referential integrity delete rule between two relations is cascade, the deletion of a record in the relation on the “many side” of the one-to-many relationship may result in the deletion of one or more records in the relation on the “one side” of the relationship.
Definition
False
Term
Referential integrity is a factor in record deletion but not in record insertion or update.
Definition
False
Term
The goal of logical database design is ____.
Definition
to create well-structured tables that properly reflect the company’s business environment
Term
Which of the following is a logical database design technique
Definition
System development.
Term
Placing the unique identifier of one database table in another existing or new table in the database ____.
Definition
creates a foreign key
may indicate the creation of a one-to-many binary relationship
may indicate the creation of a many-to-many binary relationship
Term
Converting a one-to-many binary relationship into a relational database from an E-R diagram ____.
Definition
can be done by placing the unique identifier of one of the tables into the other
Term
Converting a many-to-many binary relationship into a relational database from an E-R diagram ____.
Definition
Requires the creation of an additional table beyond the two that represent the two entities in the relationship
Term
Converting a one-to-one unary relationship into a relational database from an E-R diagram ____.
Definition
Can be done by adding another copy of the unique identifier of the single entity’s table into the same table with a different attribute name
Term
Converting a one-to-many unary relationship into a relational database from an E-R diagram ____.
Definition
Can be done by adding another copy of the unique identifier of the single entity’s table into the same table with a different attribute name
Term
Converting a many-to-many unary relationship into a relational database from an E-R diagram ____.
Definition
Can be done by adding another copy of the unique identifier of the single entity’s table into the same table with a different attribute name
Term
Converting a ternary relationship into a relational database from an E-R diagram ____.
Definition
Requires the creation of an additional table beyond the three that represent the three entities in the relationship
Term
Data normalization ____.
Definition
precedes physical database design
Term
The term that describes a non-key field of a relational table being dependent on only part of the table’s key is ____.
Definition
partial functional dependency
Term
The term that describes one non-key field of a table being dependent on another non-key field of the table is ____.
Definition
transitive dependency
Term
data in ____ has only a single attribute value in every attribute position.
Definition
all three normal forms - 1st 2nd 3rd
Term
Data in ____ cannot have transitive dependencies.
Definition
third normal form
Term
Data in ____ cannot have partial functional dependencies but can have transitive dependencies.
Definition
second normal form
Term
A relational table in second normal form ____.
Definition
is also in third normal form
Term
A relational table in third normal form ____.
Definition
Is in first and second normal form, it also has no transitive dependencies
Term
logical database design is the process of modifying the physical database design to improve performance.
Definition
False
Term
physical database design is the process of modifying the logical database design to improve performance.
Definition
False
Term
the two major logical database design techniques are conversion of E-R diagrams to relational tables and data normalization.
Definition
True
Term
a one-to-one binary relationship in an E-R diagram can be converted into either one or two tables in a relational database.
Definition
True
Term
converting a one-to-one binary relationship in an E-R diagram into a single table in a relational database introduces data redundancy.
Definition
False
Term
converting a one-to-one binary relationship in an E-R diagram into two relational tables, the rule is that the unique identifier of the entity on the “many side” of the one-to-many relationship is placed as a foreign key in the table representing the entity on the “one side.”
Definition
False
Term
a many-to-many binary relationship in an E-R diagram requires the creation of a total of three tables in a relational database.
Definition
True
Term
a one-to-one unary relationship in an E-R diagram requires the creation of a total of three tables in a relational database.
Definition
false
Term
converting from first to second normal form involves subdividing tables to remove partial functional dependencies.
Definition
true
Term
a transitive dependency occurs when a nonkey attribute determines another nonkey attribute.
Definition
true
Term
in third normal form, all foreign keys appear where needed to logically tie together related tables.
Definition
true
Term
in first normal form a single, generally multi-attribute, key is chosen that defines or determines all of the other attributes.
Definition
true
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