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This is a ppt on introductory overview on data warehousing.
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By-By-
Ms.Vishakha AgarwalMs.Vishakha Agarwal
(B-tech 3(B-tech 3rdrd yr , CSE) yr , CSE)
Roll no:1035210106Roll no:1035210106
Data Warehousing and its need. Data Warehouse DBMS Vs. Data Warehouses Architecture Data Warehouse Components Data Warehouse -data characteristics Data Warehousing tools Advantages Disadvantages
We will discuss We will discuss about… about…
Definition :- It is a technology that allows us to gather , store & present data in a form suitable for human exploration.
Need:- It was needed by big organizations for data analysis.
Data Warehousing and its Data Warehousing and its needneed
It is a –
Subject-oriented Integrated Time-variant Non-volatile collection of data to support decision-making
process of an enterprise. It is a multi-dimensional model.
Data WarehouseData Warehouse
DBMS Vs. Data DBMS Vs. Data WarehousesWarehouses
DBMS Focuses on present.
Use of atomic data. Each transaction
accesses only small amount of data.
Supports day-to-day operations.
Changing ,incomplete data.
Data Warehouse
Focuses on past , present and future.
Use of aggregate data. Most analysis targets
large amounts of data. Supports information
analysis. Static ,historic data.
ArchitectureArchitecture
There are four characteristics of data in data warehouses.
Subject-oriented Data
Integrated Data
Time-variant Data
Non-volatile Data
Granular Data
Data Warehouse-Data Data Warehouse-Data characteristicscharacteristics
Extract transform load tools(ETL)
Data Warehousing Data Warehousing toolstools
Data cleaning
Integration tool
Quality-management tool
Query tool
Reporting tool
Other tools…Other tools…
Very large storage. Enhances end-user access to a wide variety of
data. Potentially lower computing costs and
increased productivity. Providing a place to combine related data from
separate sources. Security: data and access. Query processing: multiple options.
AdvantagesAdvantages
It is a costly method.
Data warehouses can get outdated relatively
quickly.
Lack of flexibility.
Data warehouses are not the optimal environment
for unstructured data.
Difficult to accommodate changes in data types and
ranges, data source schema, indexes and queries.
DisadvantagesDisadvantages