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.