MIS Chapter 3

structured query language

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

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.

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.

data warehouse

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

database

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

logical structure

is a data model of a specific problem domain expressed independently of a particular database management product or storage technology but in terms of data structures.

foreign key

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

big data

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

raw data

is data that has not been processed for use.

database engine

is responsible for data storage, manipulation, and retrieval.

network model

is 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

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

data hierarchy

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

data manipulation

is used to add, delete, modify, and retrieve records from a database.

data mining analysis

is used to discover patterns and relationships

online transaction processing

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

data mart

is usually a smaller version of a data warehouse, used by a single department or function.

data warehouse extraction

means collecting data from a variety of sources and converting it into a format that can be used in transformation processing.

or operator

means only one of the conditions must be met

and operator

means that all conditions must be met

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 process 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, and delete

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

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 recorda from a treelike structure. 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.

primary key

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

data definition component

used to create and maintain the data dictionary and define the structure of files in a database.

relational model

uses 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).

business analytics

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

query by example

you 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.