Bill Inmon Alin first coined data Warehouse in 1990. According to him, a data warehouse Is a subject-oriented, integrated, time-variant, and non-volatile collection of data. Data warehouse is kept separate from organization operational database and it can be said that a data warehouse is a more extensive form of DBMS data.
Key Points
- There is no requirement for frequent updating of data on the warehouse.
- These data help analysts to make informed decisions in an organization.
- Data warehouses provide generalized and combined data in a multidimensional view
- Data warehouse also provides us with online analytical processing(OLAP) tools Which help in interactive and effective analysis.
Characteristics of Data warehouse
- Subject-oriented
- Non-volatile
- Integrated
- Time variant
Read More About: Characteristics of Data warehouse
KDD process
- KDD stands for Knowledge discovery from data.
- KDD refers to the overall process of discovering useful knowledge from data.
Data Cleaning
Data cleaning is defined as the removal of noisy and irrelevant data from the collection.
- Cleaning missing values
- Cleaning noisy data
Data integration
Data integration is defined as the heterogeneous data from multiple sources combined into a common source.
Data Selection
Data selection is defined as the process where data relevant to the analysis is decided and retrieved from the data warehouse.
Data Transformation
Transformation is defined as the process of transforming data into the appropriate required form required by the mining procedure.
Data objects and attributes types
- Data sets are made up of data objects.
- A data object represents an entity.
Data objects are described by attributes in the database.
Attributes: A data field, represents a characteristic or feature of a data object.
Types of attributes
- Nominal attributes:
- Relating to names
- Each value represents some kind of category, code, or state.
- Also referred to as categorical attributes.
- Binary attributes:
- Nominal attributes with only two categories of state(0 and 1).
Important Resources
- Data Warehouse Interview Questions
- Components of Data Warehouse
- Data Warehouse Tools
- Difference Between Data Warehouse and Data Mart
Data Warehousing MCQ
What is the time horizon in the data warehouse?
Real-Life Problems
Prep for Target Roles
Custom Plan Duration
Flexible Plans
Under which of the following does the pattern evaluation issue fall?
What does a null value indicate?
What does data mining system classification consist of?
What does DMQL stand for?
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What does OLTP stand for?
What is a multidimensional database also known as?
Topic Buckets
Mock Assessments
Reading Material
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What is a query tool made for?
What is known as the heart of the warehouse?
What is the percent of data redundancy between environments?
What is the source of all data warehouse data known as?
What is the technology area associated with CRM known as?
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The data is stored, retrieved and updated in ____________.
What is the use of data cleaning?
Where can the data be updated?
Where is data warehousing used?
Which of the following is a method of incremental conceptual clustering?
Which of the following is included in in@active. data warehouse architecture?
Which of the following is not a clustering method.
Which of the following maps the core warehouse metadata to business concepts, familiar and useful to end-users.
Which of the following technology is not well suited for data mining?
Who is responsible for running queries and reports against data warehouse tables?
______ is an object-oriented, integrated, time-variant, and nonvolatile collection of data in support of management decisions.
Choose the incorrect property of the data warehouse.
Choose the option on which database architecture is based.
DSS in data warehouse stands for _____________.
ETL stands for ____________
From where are classification rules extracted?
From where are classification rules extracted?
From where does the source data from the warehouses come?
How many approaches are there in data warehousing to integrate heterogeneous databases?
Identify among the following for which system of data warehousing is mostly used.
Identify the correct definition of Reconciled data.
Identify the correct option which defines Datamart.
Among the following which is the specialized data warehouse database?
Identify the most common source of change data in refreshing a data warehouse.
Identify the operation which can be performed in the data warehouse.
Identify the options below that a data warehouse can include.
Identify the term used to define the multidimensional model of the data warehouse.
Identify the type of relationship between fact and dimension table in a star schema.
Identify whether True or False: Data in operational systems are typically fragmented and inconsistent.
MDDB stands for ________________
On what is data warehouse based?
Small logical units where data warehouses hold large amounts of data is known as _____
State whether True or False: Data warehouse is generally updated in real-time.
