Data and Information Management Ch 2

Terms in this set (61)

American National Standards Institute (ANSI)

the group that accepted the DBTG recommendations and augmented database standards in 1975 through its SPARC committee

a characteristic of an entity or object-has a name and a data type

a movement to find new and better ways to manage large amounts of Web-generated data and derive business insight from it, while simultaneously providing high performance and scalability at a reasonable cost

a description of a policy, procedure, or principle within an organization

a collection of similar objects with shared structure (attributes) and behavior (methods). It encapsulates an object's data representation and a method's implementation; are organized in a class hierarchy

a diagram used to represent data and their relationships in UML object notation

class diagram notation

the set of symbols used in the creation of class diagrams

class hierarchy

the organization of classes in a hierarchical tree in which each parent class is a superclass and each child class is a subclass

conceptual model

the output of the conceptual design process; provides a global view of an entire database and describes the main data objects, avoiding details

conceptual schema

a representation of the conceptual model, usually expressed graphically

the classification of the relationship between entities

a restriction placed on data, usually expressed in the form of rules

Crow's Foot notation

a representation of the entity relationship diagram that uses a three-pronged symbol to represent the "many" sides of the relationship

data definition language (DDL)

the language that allows a database administrator to define the database structure, schema, and subschema

data manipulation language (DML)

the set of commands that allows an end user to manipulate the data in the database

a representation, usually graphic, of a complex "real-world" data structure; are used in the database design phase of the Database Life Cycle

a person, place, thing, concept, or event for which data can be stored

entity instance

in ER modeling, a specific table row

entity occurrence

entity relationship diagram (ERD)

a diagram that depicts an entity relationship model's entities, attributes, and relations

entity relationship (ER) model (ERM)

a data model that describes relationships among entities at the conceptual level with the help of ER diagrams

in a relational model, a grouping of related entities

eventual consistency

a model for database consistency in which updates to the database will propagate through the system so that all data copies will be consistent eventually

extended relational data model (ERDM)

a model that includes the object-oriented model's best features in an inherently simpler relational database structural enviornment

Extensible Markup Language (XML)

a metalanguage used to represent and manipulate data elements. Unlike other markup languages, it permits the manipulation of a document's data elements; facilitates the exchange of structured documents such as orders and invoices over the Internet

the application programmer's view of the data environment; given its business focus, it works with a data subset of the global database system

external schema

the specific representation of an external view, the end user's view of the data environment

hardware independence

a condition in which a model does not depend on the hardware used in the model's implementation. Therefore, changes in the hardware will have no effect on the database design at the conceptual level

hierarchical model

an early database model whose basic concepts and characteristics formed the basis for subsequent database development. This model is based on an upside-down tree structure in which each record is called a segment. The top record is the root segment. Each segment has a 1:M relationship to the segment directly below it

in the object-oriented data model, the ability of an object to inherit the data structure and methods of the classes above it in the class hierarchy

in database modeling, a level of data abstraction that adapts the conceptual model to a specific DBMS model for implementation. It is the representation of a database as "seen" by the DBMS; it requires a designer to match the conceptual model's characteristics and constraints to those of the selected implementation model

internal schema

a representation of an internal model using the database constructs supported by the chosen database

a data model based on a structure composed of two data elements: a key and a value, in which every key has a corresponding value or set of values

a stage in the design phase that matches the conceptual design to the requirements of the selected DBMS and is therefore software-dependent. It is used to translate the conceptual design into the internal model for a selected database management system

logical independence

a condition in which the internal model can be changed without affecting the conceptual model

many-to-many (M:N) relationship

associations among two or more entities in which one occurrence of an entity is associated with many occurrences of a related entity and one occurrence of the related entity is associated with many occurrences of the first entity

in the object-oriented data model, a named set of instructions to perform an action; represent real world actions, and are invoked though messages

a data model standard created in the late 1960s that represented data as a collection of record types and relationships as predefined sets with an owner record type and a member record type in a 1:M relationship

a new generation of database management systems that is not based on the traditional relational database model

an abstract representation of a real-world entity that has a unique identity, embedded properties, and that ability to interact with other objects and itself

object-oriented data model (OODM)

a data model whose basic modeling structure is an object

object-oriented database management system (OODBMS)

data management software used to manage data in an object-oriented database model

object/relational database management system (O/R DBMS)

a DBMS based on the extended relational model

one-to-many (1:M) relationship

associations among two or more entities that are used by data models; one entity instance is associated with many instances of the related entity

one-to-one (1:1) relationship

associations among two or more entities that are used by data models; one entity instance is associated with only one instance of the related entity

physical independence

a condition in which the physical model can be changed without affecting the internal model

a model in which physical characteristics such as location, path, and format are described for the data; it is both hardware and software dependent

in a relational database model, an entity set; are implemented as tables; are related to each other through the sharing of a common entity characteristic

relational database management system (RDBMS)

a collection of programs that manages a relational database; translates a user's logical requests into commands that physically locate and retrieve the requested data; also creates and maintains a data dictionary to help provide data security, data integrity, concurrent and easy access, and system administration to the data through a query language and application programs

relational diagram

a graphical representation of a relational database's entities, the attributes within those entities, and the relationships among the entities

relational model

developed by E. F. Codd of IBM in 1970, it represented a major breakthrough for users and designers because of its conceptual simplicity; is based on mathematical set theory and represents data as independent relations; each relation (table) is conceptually represented as a matrix of intersecting rows and columns; the relations are related to each other through the sharing of common entity characteristics

an association between entities

a logical grouping of database objects, such as tables, indexes, views, and queries, that are related to each other; usually it belongs to a single user or application

in the hierarchical data model, the equivalent of a file system's record type

semantic data model

the first of a series of data models that more closely represented the real world, modeling both data and their relationships in a single structure known as an object

software independence

a property of any model or application that does not depend on the software used to implement it

a case in which the number of table attributes is very large but the number of actual data instances is low

in the network model, the portion of the database "seen" by the application programs that produce the desired information from the data in the database

a matrix composed of intersecting rows (entities) and columns (attributes) that represents an entity set in the relational model

in the relational model, a table row

Unified Modeling Language(UML)

a language based on object-oriented concepts that provides tools such as diagrams and symbols to graphically model a system

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