DATA WAREHOUSING TECHNOLOGIES , ETL Tools Informatica Ab Intio DataStage 8 IBM Infosphere

1. www.newyorksys.com
Data Warehouse…..An
Overview By Newyorksys
By

2. Contents
 Introduction to Data Warehouse
 Features of a Data Warehouse
 OLTP vs. OLAP (Transactional vs.
Analytical)
 Introduction to Dimensional Modeling
◦Fact Tables
◦Dimension Tables
◦Star Schema
◦Snow Flake Schema
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3. What is a Data Warehouse ?
Collection of diverse data
subject oriented
aimed at executive, decision
maker
often a copy of operational data
with value-added data (e.g.,
summaries, history)
integrated
time-varying
non-volatile
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4. Data Warehouse – Subject
Oriented
Organized around major
subjects, such as customer,
product, sales.
Focusing on the modeling and
analysis of data for decision
makers, not on daily
operations or transaction
processing
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5. Data Warehouse-Integrated
Constructed by integrating multiple,
heterogeneous data sources
relational databases, flat files, on-line
transaction records
Data cleaning and data integration
techniques are applied.
Ensure consistency in naming conventions,
encoding structures, attribute measures,
etc. among different data sources
E.g., Hotel price: currency, tax, breakfast covered,
etc.
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6. Data Warehouse – Non-
Volatile
 A physically separate store of data
transformed from the operational
environment.
 Operational update of data does not
occur in the data warehouse
environment.
◦ Requires only two operations in data
accessing:
 initial loading of data and access of
data.
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7. Data Warehouse - Time
Variant
The time horizon for the data warehouse is
significantly longer than that of operational
systems.
◦ Operational database: current value data.
◦ Data warehouse data: provide information
from a historical perspective (e.g., past 5-10
years)
Every key structure in the data warehouse
◦ Contains an element of time, explicitly or
implicitly
◦ But the key of operational data may or may
not contain “time element”.
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8. Advantages of Data
Warehouse
 High query performance
 Queries not visible outside warehouse
 Local processing at sources unaffected
 Can operate when sources unavailable
 Can query data not stored in a DBMS
 Extra information at warehouse
◦ Modify, summarize (store aggregates)
◦ Add historical information
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9. CONTACT US
NewyorkSys is one of the leading Training
Company in US. We have certified trainers.
We provide Online Training, Fast Track online
training, with job assistance.
For more details Visit :
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registration/
USA: +1-718-313-0499 , 718-305-1757
Email : enquiry@newyorksys.us
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