DATAWARE HOUSING AND DATA MINING Study Guide - Midterm Guide: Data Mining, Data Warehouse, Stream Processing
MODULE VI
1.What is a data stream and give its characteriscs.
A data stream means a connuous ow of data that is generated and processed in real-me. In contrast
to stac datasets, data streams are dynamic, constantly changing, and are oen produced by various
sources, such as sensors, social media, or online transacons.
Here are some of the key characteriscs of data streams:
1. Unbounded: Data streams are typically unbounded, meaning that the size of the data can grow
innitely over me, and there is no xed endpoint for the stream.
2. Connuous: Data streams are generated connuously over me, without any pause or stop.
Therefore, it is crucial to process them in real-me or near real-me to keep up with the pace
of the data.
3. Fast-moving: Data streams are oen high-speed and fast-moving, which means that they must
be processed rapidly and eciently to avoid data loss or latency.
4. Variable in volume: The volume of data generated in a data stream can vary signicantly,
depending on the source and the specic context of the data.
5. Noisy and incomplete: Data streams are oen noisy, incomplete, and contain errors, which can
make it challenging to extract meaningful insights from the data.
6. Potenally innite: Since data streams are unbounded, it is possible that they may connue to
produce data indenitely, making it impossible to analyze the enre dataset.
Overall, data streams present unique challenges and opportunies for real-me data processing and
analysis, and require specialized techniques and tools to extract useful insights and knowledge from
them.
2.What are the applicaons of data streams.
Data streams are used in data warehousing to improve the speed and eciency of data processing,
analysis, and decision-making.
Here are some examples of data streams are applied in data warehousing:
1. Real-me data integraon: Data streams can be used to integrate data from mulple sources
in real-me, allowing organizaons to make faster and more accurate decisions based on the
most up-to-date informaon.
2. Real-me analycs: Data streams can be used for real-me analycs, where queries are
applied to the data stream in real-me to idenfy paerns, trends, and anomalies.
This approach enables organizaons to detect and respond to emerging trends and issues in
real-me.
3. Event processing: Data streams can be used for event processing, where events or nocaons
are generated in real-me based on predened criteria.
This approach can help organizaons monitor crical business processes, detect anomalies,
and trigger alerts or acons as needed.
4. Connuous data warehousing: Data streams can be used to connuously update data
warehouses, allowing organizaons to make decisions based on the most up-to-date
informaon.
This approach is parcularly useful in fast-moving industries such as nance, retail, and
healthcare.
5. Real-me reporng and dashboarding: Data streams can be used to provide real-me
reporng and dashboarding, allowing organizaons to monitor key performance indicators
(KPIs) and make informed decisions based on real-me data.
Overall, data streams oer numerous opportunies to improve the eciency and eecveness of data
warehousing, and to provide real-me insights and intelligence to support decision-making and
improve business operaons.
3.Give architecture of stream query processing.
The architecture of stream query processing typically consists of several components that work
together to process and analyze data streams in real-me. Here are some of the key components:
1. Stream source: The data stream source is the inial source of the data, such as a sensor or a
data feed. The data stream is generated from this source and is connuously fed into the
system.
2. Stream processing engine: This component is responsible for processing the data stream in
real-me. The engine applies various transformaons, lters, and aggregaons to the data
stream to extract meaningful insights and perform analysis.
3. Query language: A query language is used to express the stream processing logic and to specify
the operaons that should be performed on the data stream. Common query languages for
stream processing include SQL, StreamSQL, and StreamForge.
4. Stream storage: The stream storage component is used to store and manage the incoming
stream of data. The storage system must be able to handle high volumes of data, and provide
fast retrieval and query processing capabilies.
5. Stream analycs: Stream analycs components use machine learning, stascal modeling,
and other techniques to perform real-me analysis of the data stream. This component can
be used to detect anomalies, predict outcomes, and perform other types of analysis on the
data.
6. Stream visualizaon: Stream visualizaon components provide graphical representaon of the
real-me data stream, such as charts, graphs, and dashboards. This component can help users
to quickly understand and visualize the stream data.
Overall, the architecture of stream query processing is designed to handle high-speed, high-volume,
and constantly changing data streams, and to provide real-me analysis and insights to support
decision-making and improve business operaons.
4.Explain about random sampling and histogram
Random sampling and histogram are two common techniques used in data warehousing and data
mining to analyze large data sets.
1. Random Sampling: Random sampling is a stascal technique that involves selecng a subset
of data from a larger data set at random. This technique is commonly used in data warehousing
and data mining to obtain a representave sample of the data for analysis.
Random sampling is parcularly useful when working with large data sets where it is impraccal or
me-consuming to analyze the enre data set. By selecng a smaller representave sample of the
data, analysts can sll obtain meaningful insights and make informed decisions based on the data.
Random sampling can be performed using various sampling techniques, such as simple random
sampling, straed random sampling, or cluster sampling. The choice of sampling technique will
depend on the characteriscs of the data set and the research queson being addressed.
2. Histogram: A histogram is a graphical representaon of the distribuon of a data set. The data
is grouped into intervals or bins, and the frequency of observaons within each interval is
ploed on the y-axis.
Histograms are commonly used in data warehousing and data mining to explore the distribuon of a
data set and to idenfy paerns or trends. They can be parcularly useful when working with
connuous or numerical data, such as sales data or customer demographics.
Histograms can help analysts to idenfy outliers, anomalies, or gaps in the data, as well as to idenfy
trends or paerns in the data. By analyzing the histogram, analysts can gain a beer understanding of
the data and make more informed decisions based on the data.
In summary, random sampling and histogram are two important techniques used in data warehousing
and data mining to analyze large data sets. These techniques can help analysts to obtain representave
samples of the data and to explore the distribuon of the data to idenfy paerns, trends, and
anomalies.
5.Explain about mul resoluon model and randomized algorithms
Mul-resoluon models and randomized algorithms are two important techniques used in data
warehousing and data mining to improve the eciency and accuracy of data analysis.
1. Mul-Resoluon Models: Mul-resoluon models involve represenng data at dierent levels
of abstracon or detail. This technique is parcularly useful when working with large, complex
data sets, where it may be impraccal or me-consuming to analyze the data at its full
resoluon.
Mul-resoluon models can be used to simplify the data and focus on the most important features or
paerns, while sll retaining the overall structure of the data. This can help analysts to beer
understand the data and make more informed decisions based on the data.