Q&A Hero

Q: One characteristic of generalization hierarchies is that they are implemented as _____________relationships.

Q: If one department chaira professorcan chair only one department, and one department can have only one department chair. The entities PROFESSOR and DEPARTMENT exhibit a(n)__________ relationship.

Q: ____________relationships cannot be implemented as such in the relational model.

Q: The____________ relationship is the relational database norm.

Q: The___________ catalog can be described as a detailed system data dictionary that describes all objects within the database, including data about table names, the table's creator and creation date, the number of columns in each table, the data type corresponding to each column, index filenames, index creators, authorized users, and access privileges.

Q: A(n)____________ provides a detailed description of all tables found within the user/designer-created database.

Q: A(n)____________ links tables on the basis of an equality condition that compares specified columns of each table.

Q: ____________is the real power behind the relational database, allowing the use of independent tables linked by common attributes.

Q: PRODUCT yields all possible pairs of rows from two tables, also known as the___________ product.

Q: The relational operators have the property of__________ ; that is, the use of relational algebra operators on existing relations (tables) produces new relations.

Q: To avoid nulls, some designers use special codes, known as__________ , to indicate the absence of some value.

Q: A primary key is a(n)__________ key chosen to be the primary means by which rows of a table are uniquely identified.

Q: In a relational model,________ are also used to establish relationships among tables and to ensure the integrity of the data.

Q: In a relational table, each column has a specific range of values known as the________ domain.

Q: A table is also called a(n)________ because the relational model's creator, E. F. Codd, used the two terms as synonyms.

Q: According to Codd's________ rule of relational database, "If the system supports lowlevel access to the data, users must not be allowed to bypass the integrity rules of the database."a. nonsubversionb. rule zeroc. view updatingd. information

Q: According to Codd's________ rule of relational database, "Application programs and ad hoc facilities are logically unaffected when changes are made to the table structures that preserve the original table values (changing order of columns or inserting columns)."a. nonsubversionb. logical data independencec. comprehensive data sublanguaged. integrity independence

Q: When you define a table's primary key, the DBMS automatically creates a(n)__________ index on the primary key column(s) you declared.a. keyb. compositec. uniqued. primary

Q: A(n)__________ is an orderly arrangement used to logically access rows in a table.a. primary ruleb. superkeyc. relationshipd. index

Q: Another name for a composite entity is a(n)___________ entity.a. bridgeb. linkedc. directived. associative

Q: _______________relationships can be implemented by creating a new entity in 1:M relationships with the original entities.a. 1:Nb. M:1c. M:Nd. 1:1

Q: The_________-- relationship should be rare in any relational database design.a. 1:1b. 1:Mc. M:1d. M:N

Q: The________ relationship is the "relational model ideal."a. 1:1b. 1:Mc. M:1d. M:N

Q: In a database context, a(n)________ indicates the use of different names to describe the same attribute.a. entityb. duplicatec. synonymd. homonym

Q: In a database context, the word_____________- indicates the use of the same attribute name to label different attributes.a. redundancyb. homonymc. duplicated. synonym

Q: The___________ is actually a system-created database whose tables store the user/designer-created database characteristics and contents.a. database tupleb. systematic databasec. unique indexd. system catalog

Q: A contains at least all of the attribute names and characteristics for each table in the system.a. data dictionaryb. relational schemac. logical schemad. database

Q: A(n)________ only returns matched records from the tables that are being joined.a. outer joinb. inner joinc. equijoind. theta join

Q: ___________are especially useful when you are trying to determine what values in related tables cause referential integrity problems.a. Inner joinsb. Outer joinsc. Equijoinsd. Theta joins

Q: A(n)__________join links tables by selecting only the rows with common values in their common attribute(s).a. attributeb. uniquec. foreignd. natural

Q: When two or more tables share the same number of columns, and when their corresponding columns share the same or compatible domains, they are said to be___________ .a. intersect-compatibleb. union-compatiblec. difference-compatibled. select-compatible

Q: ______________returns only the attributes requested, in the order in which they are requested.a. PROJECTb. SELECTc. UNIONd. DIFFERENCE

Q: ____________________, also known as RESTRICT, yields values for all rows found in a table that satisfy a given condition.a. INTERSECTb. UNIONc. DIFFERENCEd. SELECT

Q: To be considered minimally relational, the DBMS must support the key relational operators___________ , PROJECT, and JOIN.a. INTERSECTb. UNIONc. DIFFERENCEd. SELECT

Q: The_________ constraint can be placed on a column to ensure that every row in the table has a value for that column.a. UNIQUEb. NOT NULLc. VALUEd. EMPTY

Q: The CUSTOMER table's primary key is CUS_CODE. The CUSTOMER primary key column has no null entries, and all entries are unique. This is an example of____________ integrity.a. entityb. referentialc. relationald. null

Q: A ____________key is defined as a key that is used strictly for data retrieval purposes.a. lookupb. foreignc. candidated. secondary

Q: Referential________ dictates that the foreign key must contain values that match the primary key in the related table, or must contain null.a. integrityb. uniquenessc. modeld. attribute

Q: A______ is the primary key of one table that has been placed into another table to create a common attribute.a. superkeyb. composite primary keyc. candidate keyd. foreign key

Q: A____________ key can be described as a minimal superkey, a superkey without any unnecessary attributes.a. secondaryb. candidatec. primaryd. foreign

Q: A _______________-is any key that uniquely identifies each row.a. superkeyb. special keyc. foreign keyd. candidate key

Q: In the relational model,___________ are important because they are used to ensure that each row in a table is uniquely identifiable.a. relationsb. keysc. indexesd. logical structures

Q: Date attributes contain calendar dates stored in a special format known as the___________ date format.a. Epochb. calendarc. Juliand. logical

Q: Each table___________represents an attribute.a. columnb. rowc. dimensiond. value

Q: ________logic, used extensively in mathematics, provides a framework in which an assertion (statement of fact) can be verified as either true or false.a. Predicateb. Databasec. Relationald. Index

Q: As rare as 1:1 relationships should be, certain conditions absolutely require their use.a. Trueb. False

Q: The onetomany (1:M) relationship is easily implemented in the relational model by putting the foreign key of the "1" side in the table of the "many" side as a primary key.a. Trueb. False

Q: A data dictionary is sometimes described as "the database designer's database" because it records the design decisions about tables and their structures.a. Trueb. False

Q: The DIVIDE operation uses one singlecolumn table (e.g., column "a") as the divisor and one twocolumn table (e.g., columns "a" and "b") as the dividend.a. Trueb. False

Q: In a natural join, the column on which the join was made occurs twice in the new table. a. True b. False

Q: The DIFFERENCE operator subtracts one table from the other.a. Trueb. False

Q: The SELECT operator yields a vertical subset of a table. a. True b. False

Q: Relational algebra defines the theoretical way of manipulating table contents using relational operators.a. Trueb. False

Q: RDBMSs enforce integrity rules automatically.a. Trueb. False

Q: Depending on the sophistication of the application development software, nulls can create problems when functions such as COUNT, AVERAGE, and SUM are used.a. Trueb. False

Q: A null is created when you press the Enter key or the Tab key to move to the next entry without making a prior entry of any kind.a. Trueb. False

Q: If the attribute (B) is functionally dependent on a composite key (A) but not on any subset of that composite key, the attribute (B) is fully functionally dependent on (A). a. True b. False

Q: Only a single attribute, not multiple attributes, can define functional dependence. a. True b. False

Q: The idea of determination is unique to the database environment.a. Trueb. False

Q: Each table in a relational database must have a primary key. a. True b. False

Q: The row's range of permissible values is known as its domain. a. True b. False

Q: Character data can contain any character or symbol intended for mathematical manipulation.a. Trueb. False

Q: The order of the rows and columns is important to the DBMS.a. Trueb. False

Q: You can think of a table as a persistent representation of a logical relation.a. Trueb. False

Q: The practical significance of taking the logical view of a database is that it serves as a reminder of the simple file concept of data storage. a. True b. False

Q: Describe the conceptual model and its advantages. What is the most widely used conceptual model?

Q: Describe the three parts involved in any SQL-based relational database application.

Q: What are the sources of business rules, and what is the database designer's role with regard to business rules?

Q: What do business rules require to be effective?

Q: What components should an implementation-ready data model contain?

Q: The____________ is the representation of a database as "seen" by the DBMS.

Q: The term__________ is used to refer to the task of creating a conceptual data model that could be implemented in any DBMS.

Q: ______________is a language based on OO concepts that describes a set of diagrams and symbols used to graphically model a system.

Q: In objectoriented terms, a(n)________________defines an object's behavior.

Q: A(n)______ is a collection of similar objects with a shared structure and behavior.

Q: In_________________________ , a threepronged symbol represents the "many" side of the relationship.

Q: Each row in the relational table is known as a(n) _________________--.

Q: A(n)___________- defines the environment in which data can be managed and is used to work with the data in the database.

Q: Each column in a relation represents a(n)______________ .

Q: Each row in a relation is called a(n)_______________ .