Lecture 1 Flashcards

Introduction to DSS and data warehousing

1
Q

decision support systems

A

any computerized system that processes and analyzes data and supports decision-making in an organization

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2
Q

business intelligence (BI)

A
  • an umbrella term that combines architectures, tools, databases, analytical tools, applications, and methodologies
  • information and knowledge that enables decision making
  • relates to understanding preferences, coping with competition, identifying opportunities, enhancing efficiency
  • uses tools such as data warehousing, knowledge management, queries, analysis, data mining, visualization
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3
Q

business analytics (BA)

A

transforming data into meaningful information or knowledge to support business decision-making

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4
Q

data

A
  • internal or external
  • structured or unstructured (more than 80%)
  • items that are the most elementary descriptions of things, events and transactions
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5
Q

DSS types

Passive DSS

A

Supports decision-making processes, but it does not offer
explicit suggestions on decisions or solutions

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6
Q

DSS types

Active DSS

A

Offers suggestions and solutions

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7
Q

DSS types

Collaborative DSS

A

Operates interactively and allows decision-makers to
modify, integrate, or refine suggestions given by the system.
Suggestions are sent back to the system for validation

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8
Q

DSS types

Model-driven DSS

A

Enhances management of statistical, financial, optimization,
and simulation models.

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9
Q

DSS types

Communication-driven DSS

A

Supports a group of people working on a common task.

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10
Q

DSS types

Data-driven DSS

A

Enhances the access and management of time series of
corporate and external data.

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11
Q

DSS types

Document-driven DSS

A

Manages and processes nonstructured data in many formats

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12
Q

DSS types

Knowledge-driven DSS

A

Provides problem-solving features in the form of facts, rules,
and procedures

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13
Q

information

A

organized data that has meaning and vakue

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14
Q

knowledge

A

processed data or information that is applicable to a business decision problem

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15
Q

BA method types

descriptive analytics

A
  • use data to understand past & present
  • results in well defined problems and opportunities
  • “what happened and what is happening?”
  • business reporting, dashboards, scoreboards, data warehousing, OLAP, performance dashboard
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16
Q

BA method types

predictive analytics

A
  • predict future behavior (states and conditions) based on past performance
  • “what will happen and why will it happen?”
  • data mining, text mining, web/media mining, forecasting
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17
Q

BA method types

prescriptive analytics

A
  • make decisions or recommendations to achieve the best performance
  • “what should I do and why should I do it?”
  • optimization, simulation, decision modeling, expert systems/knowledge based systems/rule based systems, (AI)
18
Q

descriptive analytics

performance dashboard

A

provides a comprehensive visual view of corporate performance measures, trends, and exceptions

19
Q

descriptive analytics

OLAP

A

online analytical processing

20
Q

OLTP

A

online transactional processing

21
Q

ETL staging

A
  • extraction (getting the data)
  • transformation (cleaning the data)
  • loading (storing the data in a relevant environment)

getting the raw data to workable data is the most time consuming part of BI/BA/DSS; other difficulties with ETL are:
* temporary storage of data
* very complex data
* development and maintenance are time consuming
* extract & load frequencies

22
Q

data warehousing

A

a collection of methods, techniques, and tools used to support people to conduct data analyses that help with performing decision-making processes and improving information resources

23
Q

metrics

A

Perspectives (time, location, product, etc) that are relevant for management, and are used in multi-dimensional models.
We try to prevent information overload (about 6-7 metrics because of cognitive limitations)

24
Q

data warehouse process

A

a set of tasks that turn operational data into decision-making support information
* accessibility; to users not very familiar with IT and data structures
* integration of data; on the basis of a standard enterprise model
* query flexibility; to maximize the advantages obtained from the existing information
* information conciseness; allowing for target-oriented and effective analyses
* multidimensional representation; giving users an intuitive and manageable view of information
* correctness and completeness; of integrated data

25
Q

data warehouse

A

a collection of data that supports decision-making processes
* subject-oriented (for client’s analytic needs, NOT daily operations/transaction processing, excludes data that is not useful for decision making)
* integrated (uses multiple data sources to provide a unified view of all data -> cleans and integrates data -converts it to data warehouse- to ensure consistency)
* time-variant: displays snapshots of history (evolution over a long ass time)
* is not volatile (read-only database; no operational updates of data - only loading and accessing)

a data warehouse exists of tables and relationships between tables (“key relationships”), with a new database next to existing ones purely for decision making

26
Q

DBMS

A

database management system

27
Q

operational database

A

software that is designed to allow users to easily define, modify, retrieve, and manage data in real-time

28
Q

operational database properties

A
  • thousands of users
  • workload consists of preset transactions
  • can access and write to hundreds of records
  • goal depends on applications
  • data is detailed, and both numeric and text
  • data integration is application based
  • quality graded on integrity
  • only current data
  • continuous updates
  • normalized model
  • optimized for OLTP access to subset of database
29
Q

data warehouse properties

A
  • hundreds of users
  • workload consists of specific analysis queries
  • can access millions of records, mostly read-only
  • goal is decision-making support
  • RDBMS
  • data is summed up, mainly numeric
  • data integration is subject based (on the wishes of the decision makers)
  • high quality, graded on consistency
  • current and historical data
  • periodical updates (no up-to-date data)
  • denormalized and multidimensional models (+star/snowflake models)
  • pre-aggregation/pre-clustering/unstructured
  • optimized for OLTP access to most of database
30
Q

data warehouse needs to be a seperate database because?

A
  • historic data: decision systems requires historical data which operational databases do not typically maintain
  • data integration & consolidation: data warehousing requires aggregation (clustering) & summarization of data from different heterogenous sources
  • data quality: different sources use inconsistent data representations, codes and formats which have to be reconciled for decision-making

and also queries on ERPs are too taxing

31
Q

ERPs consist of

A

everyday operational/transactional processes of the company; one of the data sources in a data warehouse
* different platforms (every side and vendor has their own dialect of SQL)
* different databases
* process/product oriented (not decision oriented)
* internal/external data
* structured/unstructured data
* no integrated data
* inconsistent data/low quality
* limited historic data
* transaction processing performance is key (no space for analytical/BI queries!!)

32
Q

RDBMS

A

relational database management system

33
Q

data mart

dependent/independent

A

If the data mart feed is dependent on the central data warehouse, the data is synced. If not, the data mart is often connected to some other component (XML) on the back-end.

34
Q

data warehouse framework

data mart

A
  • focused on a single subject or line of business
  • subset of data warehouse (less dimensions, less history, less detail, less sources)
  • user group/application oriented
  • dependent & independent

variants: ROLAP database & MOLAP multi-dimensional cube

35
Q

data warehouse framework

BI front-end applications

A
  • query & reporting
  • OLAP (ROLAP, MOLAP, HOLAP, etc)
  • data mining (statistics, decision trees, neural networks, etc)
  • data visualization (graphs, animation, etc)

trends are integrated BI-suits and enterprise information portals

36
Q

data warehouse framework

meta data/master data

A

very important
* data about data: location, meaning, applied transformations, update frequency, access rights, data models, view definitions, etc
* different heterogenous sources (terrible for maintenance)

alternatives: shared repository or XML (interchange using standards)

37
Q

churning

A
38
Q

propensity to buy

A
39
Q

fraud detection

A
40
Q

customer segmentation

A
41
Q

single-layer architecture

A
42
Q

two-layer architecture

A