MIS Chapter 3: Database Systems, Data Warehouses and Data Marts

data warehouse

a collection of data from a variety of sources used to support decision-making applications and generate business intelligence.

database

a collection of related data that is stored in a central location or in multiple locations.

foreign key

a field in a relational table that matches the primary key column of another table. It can be used to cross reference tables.

structured query language

a standard fourth-generation query language used by many DBMS packages, such as Oracle 11g and Microsoft SQL Server. SQL consists of several keywords specifying actions to take.

relational model

a two-dimensional table of rows and columns of data. Rows are records (also called tuples), and columns are fields (also referred to as attributes).

data driven web site

acts as an interface to a database, retrieving data for users and allowing users to enter data in the database.

fragmentation

approach to a distributed DBMS addresses how tables are divided among multiple locations. There are three variations: horizontal, vertical, and mixed.

allocation

approach to a distributed DBMS combines fragmentation and replication, with each site storing the data it uses most often

replication

approach to a distributed DBMS has each site store a copy of the data in the organization's database.

object oriented databases

both data and their relationships are contained in a single object. An object consists of attributes and methods that can be performed on the object's data.

data model

determines how data is created, represented, organized, and maintained. It usually contains data structure, operations, and integrity rules.

database administrators

found in large organizations, design and set up databases, establish security measures, develop recovery procedures, evaluate database performance, and add and fine-tune database functions.

online analytical processing

generates business intelligence. It uses multiple sources of information and provides multidimensional analysis, such as viewing data based on time, product, and location.

primary key

identifies every record in a relational database. Examples include student ID numbers, account numbers, Social Security numbers, and invoice numbers.

normalization

improves database efficiency by eliminating redundant data and ensuring that only related data is stored in a table.

physical view

involves how data is stored on and retrieved from storage media, such as hard disks, magnetic tapes, or CDs.

logical view

involves how information appears to users and how it can be organized and retrieved.

big data

is data so voluminous that conventional computing methods are not able to efficiently process and manage it.

random access file structure

records can be accessed in any order, regardless of their physical locations in storage media. This method of access is fast and very effective when a small number of records need to be processed daily or weekly.

indexed sequential access method

records can be accessed sequentially or randomly, depending on the number being accessed. For a small number, random access is used, and for a large number, sequential access is used.

sequential access file structure

records in files are organized and processed in numerical or sequential order, typically the order in which they were entered.

inheritance

refers to new objects being created faster and more easily by entering new data in attributes.

encapsulation

refers to the grouping into a class of various objects along with their attributes and methods—meaning, grouping related items into a single unit. This helps handle more complex types of data, such as images and graphs.

extraction, transformation and loading

refers to the processes used in a data warehouse. It includes extracting data from outside sources, transforming it to fit operational needs, and loading it into the end target (database or data warehouse).

create read update delete

refers to the range of functions that data administrators determine who has permission to perform certain functions.

query by example

request data from a database by constructing a statement made up of query forms. With current graphical databases, you simply click to select query forms instead of having to remember keywords, as you do with SQL. You can add AND, OR, and NOT operators to the QBE form to fine-tune the query.

network model

similar to the hierarchical model, but records are organized differently. Unlike the hierarchical model, each record in the network model can have multiple parent and child records.

database management system

software for creating, storing, maintaining, and accessing database files. A DBMS makes using databases more efficient.

distributed database management system

stores data on multiple servers throughout an organization.

data dictionary

stores definitions, such as data types for fields, default values, and validation rules for data in each field.

hierarchical model

the relationships between records form a treelike structure (hierarchy). Records are called nodes, and relationships between records are called branches. The node at the top is called the root, and every other node (called a child) has a parent. Nodes with the same parents are called twins or siblings.

data hierarchy

the structure and organization of data, which involves fields, records, and files.

data mining analysis

used to discover patterns and relationships.

online transaction processing

used to facilitate and manage transaction-oriented applications, such as point-of-sale, data entry, and retrieval transaction processing. It generally uses internal data and responds in real time.

business analytics

uses data and statistical methods to gain insight into the data and provide decision makers with information they can act on.