Q&A Hero

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: ____________________ joins are especially useful when you are trying to determine what value(s) in related tables cause(s) referential integrity problems.

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 tablesalso 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: The following example exhibits ____________________ integrity: The CUSTOMER table's primary key is CUS_CODE. The CUSTOMER primary key column has no null entries, and all entries are unique. Similarly, the AGENT table's primary key is AGENT_CODE, and this primary key column also is free of null entries.

Q: If the foreign key contains either matching values or nulls, the table that makes use of that foreign key is said to exhibit ____________________ integrity

Q: A(n) ____________________ keycan be described as a superkey without unnecessary attributes.

Q: In the relational model, ____________________ are important because they are used to ensure that each row in a table is uniquely identifiable.

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

Q: The logical view of the relational database is facilitated by the creation of data relationships based on a logical construct known as a(n) ____________________.

Q: Codd's Rule of ____ states:If the system supports low-level access to the data, users must not be allowed to bypass the integrity rules of the databasea. Nonsubversion b. Logical Data Independence c. Comprehensive Data Sublanguaged. Integrity Independence

Q: Codd's Rule of ____ states: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. Nonsubversion b. Logical Data Independence c. 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. key b. incomplete c. uniqued. primary

Q: A(n) ____ is an ordered arrangement of keys and pointers.a. table b. superkey c. relationshipd. index

Q: Another name for a composite entity is a ____ entity.a. bridge b. linked c. directived. referring

Q: Since it is used to link the tables that originally were related in a M:N relationship, the composite entity structure includesas foreign keysat least the ____ keys of the tables that are to be linked.a. composite b. super c. primaryd. unique

Q: The ____ relationship should be rare in any relational database design.a. 1:1 b. 1:M c. M:1d. M:N

Q: The ____ relational type is the "relational model ideal."a. 1:1 b. 1:M c. M:1d. M:N

Q: In a database context, a(n) ____indicates the use of different names to describe the same attribute.a. entity b. duplicate c. synonymd. homonym

Q: In a database context, the word ____indicates the use of the same attribute name to label different attributes.a. redundancy b. homonym c. duplicated. synonym

Q: The ____ is actually a system-created database whose tables store the user/designer-created database characteristics and contents.a. meta dictionary b. schema c. data dictionaryd. system catalog

Q: A ____ contains at least all of the attribute names and characteristics for each table in the system.a. data dictionary b. relational schema c. logical schemad. join

Q: A(n) ____ join only returns matched records from the tables that are being joined.a. outer b. inner c. directd. union

Q: In an outer join, the matched pairs would be retained and any unmatched values in the other table would be left ____. a. in another table b. null c. out of the results d. with matching values from the original table

Q: The equijoin takes its name from the comparison operator ____ used in the condition.a. *b. < c. =d. >

Q: A(n) ____ join links tables by selecting only the rows with common values in their common attribute(s).a. equal b. unique c. foreignd. natural

Q: ____ yields only the rows that appear in both tables.a. INTERSECT b. UNION c. DIFFERENCEd. SELECT

Q: ____ combines all rows from two tables, excluding duplicate rows.a. INTERSECTb. UNION c. DIFFERENCEd. SELECT

Q: ____ yields a vertical subset of a table.a. PROJECTb. SELECT c. UNIONd. DIFFERENCE

Q: ____, also known as RESTRICT, yields values for all rows found in a table that satisfy a given condition.a. INTERSECT b. UNION c. DIFFERENCEd. SELECT

Q: To be considered minimally relational, the DBMS must support the key relational operators ____, PROJECT, and JOIN.a. INTERSECT b. UNION c. 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. HAS VALUE b. NOT NULL c. MUST HAVE VALUEd. NOT EMPTY

Q: A 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. entity b. referential c. completed. null

Q: All primary key entries are unique, and no part of a primary key may be ____.a. zero b. a foreign key c. nulld. a candidate key

Q: A ____ key can be described as a superkey without unnecessary attributes, that is, a minimal superkey.a. secondary b. candidate c. primaryd. foreign

Q: A ____ key is defined as a key that is used strictly for data retrieval purposes.a. lookup b. foreign c. candidated. secondary

Q: Referential ____ means that if the foreign key contains a value, that value refers to an existing valid tuple (row) in another relation.a. integrity b. uniqueness c. directiond. relations

Q: Controlled ____ makes a relational database work.a. relations b. logic c. chaosd. redundancy

Q: No data entry at all is known as a(n) ____.a. nil b. null c. emptyd. zero

Q: A ____ is any key that uniquely identifies each row.a. superkey b. special c. selectived. candidate

Q: Any attribute that is part of a key is known as a ____.a. key attributeb. logical attribute c. key determinerd. selector

Q: The attribute B is ____ the attribute A if each value in column A determines one and only one value in column B.a. logically dependent on b. owned by c. determined byd. functionally dependent on

Q: In the context of a database table, the statement "A ____ B" indicates that if you know the value of attribute A, you can look up the value of attribute B.a. contains b. is related to c. ownsd. determines

Q: In the relational model, ____ are important because they are used to ensure that each row in a table is uniquely identifiable.a. relations b. keys c. indexesd. logical structures

Q: ____ data can have only a true or false (yes or no) values.a. Logical b. Character c. Dated. Numeric

Q: Date attributes contain calendar dates stored in a special format known as the ____ date format.a. Epoch b. Calendar c. Juliand. logical

Q: A(n) ____ is perceived as a two-dimensional structure composed of rows and columns.a. table b. rowset c. attributed. intersection

Q: The relational model's creator, E. F. Codd, used the term relation as a synonym for ____.a. indexb. key c. tabled. relationship

Q: The relational database model enables you to view data ____ rather than ____.a. relationally, hierarchically b. hierarchically, relationally c. physically, logicallyd. logically, physically

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. Predicate b. Database c. Relationald. Index

Q: DBMSs use indexes for many different purposes.

Q: As rare as 1:1 relationships should be, certain conditions absolutely requiretheir use.

Q: The one-to-many (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.

Q: Current relational database software generally provides only a system catalog (and not a data dictionary).

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

Q: A data dictionary contains metadatadata about data.

Q: The DIVIDE operation uses one single-column table (e.g., column "a") as the divisor and one two-column table (e.g., columns "a" and "b") as the dividend.

Q: A left outer joinon tables CUSTOMER and AGENT yields all of the rows in the CUSTOMER table, including those that do not have a matching value in the AGENT table.

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

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

Q: Tables must have the same attribute characteristics (the columns and domains must be compatible) to be used in a UNION.

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

Q: Referential and entity integrity are two names for the same thing.

Q: RDBMSs enforce integrity rules automatically.

Q: A foreign key must exist in both tables that have a relationship.

Q: Describe a 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: When you can change the internal model without affecting the conceptual model, you have ____________________ independence.

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 object-oriented terms, a(n) ____________________ defines an object's behavior.