Ad-hoc reporting
The ability to
access information from
a database to meet
information requirements
as required. One-off
requests not satisfied
by pre-set reporting.
Agent
An application
that searches the data
and sends an alert when
a particular pattern is
found.
Aggregations
Information
stored in a data
warehouse in a
summarized form. Instead
of recording the date
and time each time a
certain product is sold,
the data warehouse could
store the quantity of
the product sold each
hour, each day, or each
week. Aggregations are
used for two primary
reasons:
- To save storage
space. Data
warehouses can get
large. The use of
aggregations greatly
reduces the space
needed to store
data.
- To improve the
performance of
business
intelligence tools.
When queries run
faster they take up
less processing time
and the users get
their information
back more quickly.
Some data warehouses
store both the
detailed information
and aggregated
information. This
takes even more
space, but gives
users the
possibility of
looking at all the
details while still
having good query
performance when
looking at
summaries.
Some systems use
aggregations for
historical data.
Perhaps detailed
data is kept on-line
for a year. After
that the detailed
data is kept in a
less accessible,
permanent storage
format, and only the
aggregated, summary
data is kept
on-line.
Aggregations are often
created as the sum of
the individual records.
You can also have
aggregations for count,
distinct count, maximum
value, and minimum
value.
Alert
A message that
is sent automatically by
a computer system when a
certain situation
occurs.
Application
A piece of
software designed to
meet a specific purpose.
Attribute
A single data
item related to a
database object. The
database schema
associates one or more
attributes with each
database entity.
Also known as:
field, column.
Example: In the
following database
table, the attributes
are
Name,
ID,
Extension
|
Name
|
ID
|
Extension
|
|
Jim |
124 |
7075 |
|
Valeri |
128 |
0853 |
|
Bob |
192 |
4214 |
Business intelligence
tools
Software that
enables business users
to see and use large
amounts of complex data.
Candidate key
A combination
of attributes that can
be uniquely used to
identify a database
record. Each table may
have one or more
candidate keys. One of
these candidate keys is
selected as the table
primary key.
Examples:
There are a large number
of candidate keys in the
sample table below. Some
of these are
SSN,
Phone Extension,
Name, SSN, and
Name, Age, SSN.
Note that
Age
is not a candidate key
in this case because Amy
and Elizabeth share the
same age.
|
Name
|
Age
|
SSN
|
Phone
Extension
|
|
Rob |
28 |
123-45-6789 |
1242 |
|
Amy |
34 |
987-65-4321 |
9281 |
|
Elizabeth |
34 |
111-22-3333 |
9312 |
|
Jim |
42 |
333-22-1111 |
3214 |
|
Mike |
29 |
999-99-9999 |
2314 |
Cardinality
In set theory,
cardinality refers to
the number of members in
the set. When
specifically applied to
database theory, the
cardinality of a table
refers to the number of
rows (or tuples)
contained in a table.
Chief Information
Officer (CIO)
The senior
executive in a company
responsible for
information management
and for delivering IT
services.
Clickstream data
Data regarding
web browsing.
Client/Server
architecture
A type of
network in which
computer processing is
distributed among many
individual PCs (clients)
and a more powerful,
central computer
(server). Clients can
share files and retrieve
data stored on the
server.
Collaborative
software
Groupware, such
as Lotus Notes or
Microsoft Exchange.
D
Data
A series of
facts or statements that
may have been collected,
stored, processed and/or
manipulated but have not
been organized or placed
into context. When data
is organized, it becomes
information. Information
can be processed and
used to draw generalized
conclusions or
knowledge.
Database
A collection of
tables. It also often
includes forms for
entering data, rules for
checking and validating
data that has been
entered, and the format
for creating informative
reports from the data in
the database.
Data cleansing
The process of
manipulating stored data
to make it more aligned.
Implies eliminating
duplication, correcting
spelling and removing
null fields.
Data-based knowledge
Knowledge
derived from data
through the use of
Business Intelligence
Tools and the process of
Data Warehousing.
Data mart
A database that
has the same
characteristics as a
data warehouse, but is
usually smaller and is
focused on the data for
one division or one
workgroup within an
enterprise.
Also Known As:
Local Data Warehouse or
Datamart.
Data migration
The process of
physically transmitting
data from one
environment to another.
Data mining
The use of
automated data analysis
techniques to uncover
previously undetected
relationships among data
items. Data mining often
involves the analysis of
data stored in a data
warehouse. Three of the
major data mining
techniques are
regression,
classification and
clustering.
Data model
The description
of the contents of a
database. It includes
tables and the
relationship between
them.
Data quality
The suitability
of data for different
requirements. When
constructing and
populating a database
the data quality must be
checked to ensure that
it meets the needs of
all the applications.
Data scrubbing
Removing errors
and inconsistencies from
data being imported into
a data warehouse.
Data transformation
The
modification of data as
it is moved into the
data warehouse.
Data warehouse
A data
warehouse is a
centralized database
that captures
information from various
parts of an
organization's business
processes. This
information can later be
analyzed to determine
predictive relationships
through the use of data
mining techniques.
Data warehousing
management
The on-going
supervision of the data
warehousing process.
Database Management
System (DBMS)
The software
that is used to store,
access, and manage data.
Decision support
system (DSS)
A computer
system designed to
assist an organization
in making decisions.
Dimension
The separation
of data according to
different view. A
logical designation of
related information that
applies a hierarchy for
access and reporting.
Domain
The set of all
allowable values that
attribute may assume.
Drill down and drill
up
The ability to
move between levels of
the hierarchy when
viewing data with an
OLAP browser.
- Drill down -
Changing the view of
the data to a
greater level of
detail.
- Drill up -
Changing the view of
the data to a higher
level of
aggregation.
Enterprise resource
planning
An integrated
system of operation
applications combining
logistics, production,
distribution, contract
and order management,
sales forecasting, and
financial and HR
management.
Entity
A single object
about which data can be
stored. It is the
"subject" of a table.
Entities and their
interrelationships are
modeled through the use
of entity-relationship
diagrams.
Electronic Data
Interchange (EDI)
Electronic
transmission of
documents through
point-to-point
connections using a set
of standard forms,
messages and data
elements; this can be
via leased lines,
private networks or the
Internet.
Fact table
In a star
schema, the central
table which contains the
individual facts being
stored in the database.
Field
The most basic
structural unit of a
database. It is a
container for a piece of
data. In most cases,
only a single logical
piece of data fits in
each field.
Flat file
A data file
that contains records
with no structured
relationships.
Additional knowledge is
required to interpret
these files such as the
file format properties.
Modern database
management systems used
a more structured
approach to file
management (such as one
defined by the
Structured Query
Language) and therefore
have more complex
storage arrangements.
Form
A database form
can be used to
facilitate database data
entry and/or retrieval
operations. A database
developer/administrator
usually designs a form
which can then be used
by personnel without any
specific database skills
to perform repetitive
tasks.
Front end
Tools that
enable users to interact
with underlying
application processes or
more complex programs
through a familiar,
easy-to-use interface.
Gateway
This is the
interface between
different computer
network, (usually
translates from one
network protocol to
another).
Granularity
The level of
detail of the facts
stored in a data
warehouse.
Hardware
The magnetic,
mechanical and
electrical components of
a computer and its
peripheral devices.
Hierarchy
Organization of
data into a logical tree
structure.
Index
A database
feature used for
locating data quickly
within a table. Indexes
are defined by selecting
a set of commonly
searched attribute(s) on
a table and using the
appropriate
platform-specific
mechanism to create an
index.
Example:
Personnel information
may be store in a Human
Resource department's
employee table. Clerks
find that they often
search the table for
employees by last name
but get slow query
responses. Defining an
index on the table
consisting of the last
name attribute would
speed up these queries.
Information
technology (IT)
The hardware
and software used to
process information.
Key
A field that
contains a unique
identifier for each row
in a data table. Even
though each individual
record represents a
separate piece of data,
some of those records
may look identical. A
key provides a
completely unambiguous
way to distinguish
between distinct
records, and more
importantly, serves as a
pointer to a particular
record in the table. In
many cases, data table
keys are constructed by
simply adding an
additional field to
function as the key.
Legacy system
A computer
system that's been
around for a while.
Level
The hierarchies
in dimensions have
levels which can be used
to view data at various
levels of detail.
Examples:
- A Time dimension
could have levels
for Year, Quarter,
Month, and Day.
- A Product
dimension could have
levels for Product
Family, Product
Category, Product
Subcategory, and
Product Name.
- A Customer
Geography dimension
could have levels
for Region, Country,
District, State,
City and
Neighborhood.
Local database
warehouse
A database that
has the same
characteristics as a
data warehouse, but is
usually smaller and is
focused on the data for
one division or one
workgroup within an
enterprise.
Mainframe
The central
processing unit of a
large computer, usually
receiving input from a
number of terminals.
Member
One of the data
points for a level of a
hierarchy of a
dimension.
Example:
Some of the members of
the Month level of the
Time dimension are
January, February,
March, and April.
Metadata
A term that
literally means "data
about data." This term
refers to information
about data itself --
perhaps the origin,
size, formatting or
other characteristics of
a data item. In the
database field, metadata
is essential to
understanding and
interpreting the
contents of a data
warehouse.
Microprocessors
Complex
electronic circuits that
comprise a computer's
central information
processing unit.
Multidimensional
database management
system (MDBMS)
A database
management system that
organizes data
multidimensionally.
Non-volatile
Data that does
not change.
Normalization
The process of
structuring relational
database schema such
that most ambiguity is
removed. The stages of
normalization are
referred to as normal
forms and progress from
the least restrictive
(First Normal Form)
through the most
restrictive (Fifth
Normal Form). Generally,
most database designers
do not attempt to
implement anything
higher than Third
Normal.
OLAP (on-line
analytical processing)
The use of
computers to analyze an
organization's data.
OLAP browser
A tool used for
multidimensional (OLAP)
browsing.
OLAP system
Term that is
used as a synonym for
datawarehousing system.
OLTP (online
transaction processing)
The use of
computers to run the
on-going operation of a
business.
Program
A set of
digitally coded
definitions and
instructions that
enables a computer to
perform a particular
task.
Protocol
The language
that one computer uses
to communicate with
another.
Query
The primary
mechanism for retrieving
information from a
database and consist of
questions presented to
the database in a
predefined format. Many
database management
systems use the
(Structured Query
Language) standard query
format.
Record or a row
The fields in a
record provide a
complete description of
each item in a
collection. A record is
a unique instance of
data about an object or
event.
Relationships
The connections
between records in
different data tables
are provided by
relationships.
-
One-to-Many
Relationship: The
most common
relationship between
two tables. In this
situation, precisely
one record in data
table A is related
to a number of
records in data
table B. The primary
key of table A is
inserted as a field
into table B where
it serves as a
foreign key.
Relationships
between tables are
always made through
keys.
-
One-to-One
Relationship: Each
record in one table
is linked to one and
only one record in
another table. In
many cases, one of
the tables is set of
data about a subset
of the entities in
the main table.
-
Many-to-Many
Relationship: Table
design rounds out
the possible ways of
designing data
relationships. In
some situations,
multiple entries in
a data table are
related to multiple
entries in another
data table. The
classic example is a
database of classes
and students. Each
class consists of
many students and
each student can
take many classes,
so in designing a
database to track
student and class
information, a
many-to-many design
is necessary.
The distinguishing
characteristic of
many-to-many
relationships between
two tables is that they
require a third table to
make the relationship.
Simply putting the key
from one table into the
other table would result
in a lot of duplicated
information, so a
linking table is used to
connect the tables. The
linking table simply
stores the primary key
from one table with the
primary key of its
related entry from the
second table, along with
any other information
unique to the
relationship.
Relational database
management system
(RDBMS)
A Database
Management System is
based on relational
theory. Most modern
Database Management
Systems (Oracle, Sybase,
Microsoft SQL Server)
are relational
databases. These
databases support a
standard language - SQL
(Structured Query
Language).
Replication
The physical
copying of data from one
database to another.
Scale, scalable, and
scalability
Having to do
with the ability of a
computer system or a
database to operate
efficiently with larger
quantities of data.
Scalability is often
discussed in situations
when multiple processors
are joined together. The
system scales well (or
is scalable) if doubling
the number of processors
also doubles the speed
at which the system
performs its tasks. The
extra work involved in
coordinating larger
systems usually prevents
them from being fully
scalable - so that going
from one to two
processors would
increase the total speed
by less than a factor of
two.
Schema
The logical
organization of data in
a database.
Shared dimension
In Microsoft
Analysis Services, a
dimension used by more
than one cube.
Slowly changing
dimensions (SCD)
A dimension
that has levels or
attributes that are
changing on an
occasional basis.
Software
The programs
that are run on a
computer system.
Star schema (business
definition)
A method of
organizing information
in a data warehouse that
allows the business
information to be viewed
from many perspectives.
The star is a picture of
the way the data is
being stored. The basic
factual information is
in the middle of the
star. The points of the
star represent various
perspectives from which
the factual information
can be viewed.
Structured query
language (SQL)
An
industry-standard
language used for
manipulation of data in
a relational database.
The major SQL commands
of interest to database
users are Select,
Insert, Join and Update.
Summary tables
Tables used to
store summarized or
aggregated data.
Supercomputer
An extremely
powerful computer;
designed to deal with
large amounts of data at
very high speed, often
used for military or
scientific tasks.
Table
The formal name
given to the group of
records that contain the
elements of the
collection. A table
normally represents a
distinct object
(business clients or
library books), or an
event (product orders or
stock prices).
Time-variant data
Data that is
identified with a
particular time period.
Time-variant is one of
the original defining
characteristics of a
data warehouse.
XML
XML is the
eXtensible Markup
Language -- a system
created to define other
markup languages. For
this reason, it can also
be referred to as a
metalanguage. XML is
commonly used on the
Internet to create
simple methods for the
exchange of data among
diverse clients.
