Database Notes 4

Database notes 6 _______ is the result of revealing the meaning of raw facts. information End-user data is_____? raw facts of interest to the end user ___ provide a description of the data characteristics and the set of relationships that link the data found within the database. metadata __ __ exists when different versions of the same data appear in different places. data inconsistency The response of the DBMS to a query is the . query result set Data warehouse contains historical data obtained from the . operational database data exist in the format in which they were collected. unstructured data ___ data exist in a format that does not lend itself to processing that yields information. unstructured ______ is defined as the condition in which all of the data in the database are consistent with the real-world events and conditions. data integrity The term refers to an organization of components that define and regulate the collection, storage, management and use of data within a database environment. database system Business rules are derived from ____. a detailed description of an organization's operations A noun in a business rule translates to a(n) ____ in the data model. entity A verb associating two nouns in a business rule translates to a(n) ____ in the data model. relationship A(n) ____ represents a particular type of object in the real world. entity The ____ model was developed to allow designers to use a graphical tool to examine structures rather than describing them with text. entity relationship A(n) ____ is anything about which data are to be collected and stored. entity A(n) ____ is the equivalent of a field in a file system. attribute A(n) ____ is bidirectional. relationship ____ are important because they help to ensure data integrity. constraints Students and classes have a ____ relationship. many-to many The logical view of the relational database is facilitated by the creation of data relationships based on a logical construct known as a(n) _______. relation In a relational table, each column has a specific range of values known as the _______ domain. attribute In the relational model, _______ are important because they are used to ensure that each row in a table is uniquely identifiable. keys Attribute A determines attribute B (that is, B is functionally _______ on A) if all of the rows in the table that agree in value for attribute A also agree in value for attribute B. dependent A(n) _______ key can be described as a superkey without unnecessary attributes. candidate If the foreign key contains either matching values or nulls, the table that makes use of that foreign key is said to exhibit _______ integrity referential To avoid nulls, some designers use special codes, known as _______, to indicate the absence of some value. flags The relational operators have the property of _______; that is, the use of relational algebra operators on existing relations (tables) produces new relations. closure PRODUCT yields all possible pairs of rows from two tables—also known as the _______ product. cartesian The _______ is the real power behind the relational database, allowing the use of independent tables linked by common attributes. JOIN A(n) _______ links tables on the basis of an equality condition that compares specified columns of each table. equijoin The _______ joins are especially useful when you are trying to determine what value(s) in related tables cause(s) referential integrity problems. outer A(n) _______ provides a detailed description of all tables found within the user/designer-created database. data dictionary The _______ relationship is the relational database norm. 1:M If one department chair—a professor—can chair only one department and one department can have only one department chair, then the entities PROFESSOR and DEPARTMENT exhibit a(n) _______ relationship. 1:1 The _______ relationships can be implemented by creating a new entity in 1:M relationships with the original entities. M:N The proper use of _______ keys is crucial to controlling data redundancy. foreign A(n) _______ is an orderly arrangement used to logically access rows in a table. index The index key can have multiple attributes, this is called a(n) _______ index. composite Codd's rule of _______ states that every value in a table is guaranteed to be accessible through a combination of table name, primary key value, and column name guaranteed access The Chen model is especially useful to illustrate the database from a(n) ____ perspective. conceptual Successful database design is, first and foremost, based on ____ requirements. end-user A derived attribute ____. need not be physically stored within the database Cardinality expresses ____ number of entity occurrences associated with one occurrence of the related entity. the specific A ____ attribute can be further subdivided to yield additional attributes. a composite If an entity can exist apart from one or more related entities, it is said to be ____independent. existence A ____ relationship exists when two entities are associated. binary The set of possible values for an attribute is a ____. domain What type of attribute cannot be created in a DBMS? multivalued A relationship name should be a(n) ____. a verb From a structural point of view, 2NF is better than this. 1NF It produces a lower normal form. denormalization It causes data redundancies of data on every row entry. duplication Any attribute whose value determines other values within a row. determinant A process to help reduce the likelihood of data anomalies. normalization It derives its name from the fact that a group of multiple entries of the same type can exist for any single key attribute occurrence. repeating group Any attribute that is at least part of a key. prime attribute A diagram that depicts all dependencies found within a given table structure. dependency diagram A dependency based on only a part of a composite primary key. partial dependency Refers to the level of detail represented by the values stored in a table's row. granularity Relational models view the data as part of a table or collection of tables in which all key values must be identified. true Repeating groups must be eliminated by making sure that each row defines a single entity. true Converting a database format from 1NF to 2NF is a complex process. false A table is in 2NF if it is in 1NF and it includes no partial dependencies. true It is possible for a table in 2NF to exhibit transitive dependency, where one or more attributes may be functionally dependent on non-key attributes. true Denormalization is a process for assigning attributes to entities. false Dependencies that are based on only a part of a composite primary key are called transitive dependencies. false Repeating groups must be eliminated by making sure that each column defines a single entity. false All relational tables satisfy the 1NF requirements. true Atomic attributes are attributes that can be further divided. false