Database Systems Mid-term Review Ch 1-4 & 6

Database Management System

(DBMS) A collation of programs that manages the structure and controls access to the data (Dictatorship)

Structured Query Language

(SQL) allows the user to specify what must be done without specifying how

Operational Database

(Transactional Database, Production Database, OCTP)Primarily support a companies day to day operations (Nine West Sales rep must use the POS system to check out their customers daily)

Extensible Mark-up Language

(XML) A metalanguage used to represent and manipulate data elements (Color- White: <Colors> <Colors1>White</Colors1> )

How are databases classified?

-Number of users -Database location(s) -Expected Type and extend of use

Constraint

A restriction placed on the data

Classes

Collection of similarobjects with shared structure and behavior

DDL

Data Definition Language enables the database administrator to define the scheme componets

OODM (object-oriented data model) is the basis for OODBMS

Semantic data model Object Attributes Classes Inheritance UML

Database

Shared integrated computer structure that stores end user data and metadata

Single-user Database

Supports 1 user at a time (Starbucks Bathroom)

Distributed Database

Supports data Distributed across several different sites (State police support the police force in west Bloomfield, Pontiac, Detroit, Southfield, etc)

Centralized Database

Supports data located at a single site (West bloomfield Police Station only supports west bloomfield township)

Multi-user Database

Supports multiple users at a time (Tigers stadium bathroom)

DML

Data Manipulation Language defines the environment where the data can be managed and utilized

Entity

Data collected and stored about a Person, Place, thing or event (Beyonce)

Unstructured Data

Data in the state it was collected (Similar to end user Data)

Inheritance

OODM the ability of an object to inherit the data structure and methods of the class above it in the class hierarchy

Subschema

Part seen by application programs that produce the desired info within the database

What are the two meaning of logical data structure?

Relationship between entieies Relationship between attributes when you have relationship between attributes you can have normalization

Sematic Data Model

Based on relationships between stored symbols and real world

Schema

Conceptual Organization of database for database administrator

Relationship

Describes association among entities (Beyonce owns one car)

Connectivity

The classification of the relationship between entities. Classifications include 1:1, 1:M, M:N

Business Rule

A brief, precise, unambiguous description of a policy, procedure, or principle within a specific organizations environment

Sparse data

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

Data Redundancy

A condition in which a data environment contains redundant data

Data Integrity

A condition in which the data in the database comply with all entity and referential integrity constraints

Key-value data model

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. The key value data model is also called the associative or attribute-value data model

Entity Relationship Diagram

A diagram that depicts an entity relationship models entities, attributes, and relationships

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

Big Data

A movement to find new and better ways to manage large amounts of web0generated data and derive business insight from it, while simultaneously prodiving high performance and scalability at a reasonabe cost

Data Warehouse

A warehouse with a collection of data to support decision making (Congress supports the President in decision making)

Structural Dependence

Access to a file is dependent on it's structure

Collection of tables

All data is stored in tables. The tables "present" the data to the end user in a way that is easy to understand. Tables independent races in different tables are related by common values in common attributes

End-user Interface

Allows end user to interact with the data. Each interface is a product of the software vendors idea of meaningful interaction

Object

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

Attribute

Characteristic of entity (Beyonce's Car)

Attributes

Characteristics of an entity or object has a name and data type

Data Independence

Condition: Data access is unaffected by changes on the physical data storage Characteristics

Data Dependence

Condition: Data representation and manipulation that is dependent on the physical data storage characteristics

Data Dictionary

DBMS component that contains data definitions, characteristics, and relationships

Semi-structured Data

Data that has been processed to some extent

Metadata

Data- Description of data characteristics and relationships

Data Inconsistency

Different versions of the same data yield different results

What do SQL Based Relationship database application involves what parts?

End-user interface Set of tables stored in the database SQL "engine"

Structural Independence

Exist when you can change a file structure without affecting the other application ability to access the data

Structured Data

Formatted unstructured data to facilitate storage, use and the generation of info (End user data that has been placed in respective categories to give it meaning and facilitate understanding)

Deletion Anomolies

Happen when deletion of unwanted information causes wanted information to be deleted as well.

Update Anomolies

Happen when someones information needs to get updated in multiple places within the database

What are the five major parts of a database system?

Hardware Software People Procedures Data

Insertion Anomolies

Insterting vital data into the database is not possible because the data is not there

UML

Language based on OODM concepts that provide tools such as disgrams and symbols to graphically model a system

Relational Data Management System

Manages all of the physical details, while the use while the users see the relational database as a collection of tables in which data is stored enables the user to manipulate and query the data in away

Hierarchical Model

Manages large amounts of data for complex manufacturing projects

Data Anomaly

Not all of the required changes in the redundant data are made successfully (Anomalies include: Update, Insertion, and deletion)

End-user Data

Raw Facts

Network Model

Represents complex data relationships more effectively than the hierarchical model to improve database performance, and to impose a database standard (Schema, Subschema, DML, DDL)

SQL Engine

hidden form end user the SQL engine executes all queries, or data requests. Part of the DBMS software. The end uses SQL to create table structures and to perform data access ad table maintenance. SQL engine processes all user requests-largely behind the seems and without the end user's knowledge.