Data Science Cheatsheet 💪
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🚀🔥 𝗕𝗲𝗰𝗼𝗺𝗲 𝗮𝗻 𝗔𝗴𝗲𝗻𝘁𝗶𝗰 𝗔𝗜 𝗕𝘂𝗶𝗹𝗱𝗲𝗿 — 𝗙𝗿𝗲𝗲 𝗖𝗲𝗿𝘁𝗶𝗳𝗶𝗰𝗮𝘁𝗶𝗼𝗻 𝗣𝗿𝗼𝗴𝗿𝗮𝗺
Master the most in-demand AI skill in today’s job market: building autonomous AI systems.
In Ready Tensor’s free, project-first program, you’ll create three portfolio-ready projects using 𝗟𝗮𝗻𝗴𝗖𝗵𝗮𝗶𝗻, 𝗟𝗮𝗻𝗴𝗚𝗿𝗮𝗽𝗵, and vector databases — and deploy production-ready agents that employers will notice.
Includes guided lectures, videos, and code.
𝗙𝗿𝗲𝗲. 𝗦𝗲𝗹𝗳-𝗽𝗮𝗰𝗲𝗱. 𝗖𝗮𝗿𝗲𝗲𝗿-𝗰𝗵𝗮𝗻𝗴𝗶𝗻𝗴.
👉 Apply now: https://go.readytensor.ai/cert-551-agentic-ai-certification
Master the most in-demand AI skill in today’s job market: building autonomous AI systems.
In Ready Tensor’s free, project-first program, you’ll create three portfolio-ready projects using 𝗟𝗮𝗻𝗴𝗖𝗵𝗮𝗶𝗻, 𝗟𝗮𝗻𝗴𝗚𝗿𝗮𝗽𝗵, and vector databases — and deploy production-ready agents that employers will notice.
Includes guided lectures, videos, and code.
𝗙𝗿𝗲𝗲. 𝗦𝗲𝗹𝗳-𝗽𝗮𝗰𝗲𝗱. 𝗖𝗮𝗿𝗲𝗲𝗿-𝗰𝗵𝗮𝗻𝗴𝗶𝗻𝗴.
👉 Apply now: https://go.readytensor.ai/cert-551-agentic-ai-certification
www.readytensor.ai
Agentic AI Developer Certification Program by Ready Tensor
Learn to build chatbots, AI assistants, and multi-agent systems with Ready Tensor's free, self-paced, and beginner-friendly Agentic AI Developer Certification. View the full program guide and how to get certified.
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Overfitting vs Underfitting 🎯
Why do ML models fail? Usually because of one of these two villains:
Overfitting: The model memorizes training data but fails on new data. (Like a student who memorizes past exam questions but can’t handle a new one.)
Underfitting: The model is too simple to capture patterns. (Like using a straight line to fit a curve.)
The sweet spot? A model that generalizes well.
Note: Regularization, cross-validation, and more data usually help fight these problems.
Why do ML models fail? Usually because of one of these two villains:
Overfitting: The model memorizes training data but fails on new data. (Like a student who memorizes past exam questions but can’t handle a new one.)
Underfitting: The model is too simple to capture patterns. (Like using a straight line to fit a curve.)
The sweet spot? A model that generalizes well.
Note: Regularization, cross-validation, and more data usually help fight these problems.
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Want to make a transition to a career in data?
Here is a 7-step plan for each data role
Data Scientist
Statistics and Math: Advanced statistics, linear algebra, calculus.
Machine Learning: Supervised and unsupervised learning algorithms.
xData Wrangling: Cleaning and transforming datasets.
Big Data: Hadoop, Spark, SQL/NoSQL databases.
Data Visualization: Matplotlib, Seaborn, D3.js.
Domain Knowledge: Industry-specific data science applications.
Data Analyst
Data Visualization: Tableau, Power BI, Excel for visualizations.
SQL: Querying and managing databases.
Statistics: Basic statistical analysis and probability.
Excel: Data manipulation and analysis.
Python/R: Programming for data analysis.
Data Cleaning: Techniques for data preprocessing.
Business Acumen: Understanding business context for insights.
Data Engineer
SQL/NoSQL Databases: MySQL, PostgreSQL, MongoDB, Cassandra.
ETL Tools: Apache NiFi, Talend, Informatica.
Big Data: Hadoop, Spark, Kafka.
Programming: Python, Java, Scala.
Data Warehousing: Redshift, BigQuery, Snowflake.
Cloud Platforms: AWS, GCP, Azure.
Data Modeling: Designing and implementing data models.
#data
Here is a 7-step plan for each data role
Data Scientist
Statistics and Math: Advanced statistics, linear algebra, calculus.
Machine Learning: Supervised and unsupervised learning algorithms.
xData Wrangling: Cleaning and transforming datasets.
Big Data: Hadoop, Spark, SQL/NoSQL databases.
Data Visualization: Matplotlib, Seaborn, D3.js.
Domain Knowledge: Industry-specific data science applications.
Data Analyst
Data Visualization: Tableau, Power BI, Excel for visualizations.
SQL: Querying and managing databases.
Statistics: Basic statistical analysis and probability.
Excel: Data manipulation and analysis.
Python/R: Programming for data analysis.
Data Cleaning: Techniques for data preprocessing.
Business Acumen: Understanding business context for insights.
Data Engineer
SQL/NoSQL Databases: MySQL, PostgreSQL, MongoDB, Cassandra.
ETL Tools: Apache NiFi, Talend, Informatica.
Big Data: Hadoop, Spark, Kafka.
Programming: Python, Java, Scala.
Data Warehousing: Redshift, BigQuery, Snowflake.
Cloud Platforms: AWS, GCP, Azure.
Data Modeling: Designing and implementing data models.
#data
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Advanced SQL Optimization Tips for Data Analysts
1. Use Proper Indexing
Create indexes on frequently queried columns to speed up data retrieval.
2. Avoid `SELECT *`
Specify only the columns you need to reduce the amount of data processed.
3. Use `WHERE` Instead of `HAVING`
Filter your data as early as possible in the query to optimize performance.
4. Limit Joins
Try to keep joins to a minimum to reduce query complexity and processing time.
5. Apply `LIMIT` or `TOP`
Retrieve only the required rows to save on resources.
6. Optimize Joins
Use
7. Use Temporary Tables
Break large, complex queries into smaller parts using temporary tables.
8. Avoid Functions on Indexed Columns
Using functions on indexed columns often prevents the index from being used.
9. Use CTEs for Readability
Common Table Expressions help simplify nested queries and improve clarity.
10. Analyze Execution Plans
Leverage execution plans to identify bottlenecks and make targeted optimizations.
Happy querying!
1. Use Proper Indexing
Create indexes on frequently queried columns to speed up data retrieval.
2. Avoid `SELECT *`
Specify only the columns you need to reduce the amount of data processed.
3. Use `WHERE` Instead of `HAVING`
Filter your data as early as possible in the query to optimize performance.
4. Limit Joins
Try to keep joins to a minimum to reduce query complexity and processing time.
5. Apply `LIMIT` or `TOP`
Retrieve only the required rows to save on resources.
6. Optimize Joins
Use
INNER JOIN instead of OUTER JOIN whenever possible.7. Use Temporary Tables
Break large, complex queries into smaller parts using temporary tables.
8. Avoid Functions on Indexed Columns
Using functions on indexed columns often prevents the index from being used.
9. Use CTEs for Readability
Common Table Expressions help simplify nested queries and improve clarity.
10. Analyze Execution Plans
Leverage execution plans to identify bottlenecks and make targeted optimizations.
Happy querying!
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Cheat sheets for Machine Learning and Data Science interviews
❤12👍5
SQL isn't easy!
It’s the powerful language that helps you manage and manipulate data in databases.
To truly master SQL, focus on these key areas:
0. Understanding the Basics: Get comfortable with SQL syntax, data types, and basic queries like SELECT, INSERT, UPDATE, and DELETE.
1. Mastering Data Retrieval: Learn advanced SELECT statements, including JOINs, GROUP BY, HAVING, and subqueries to retrieve complex datasets.
2. Working with Aggregation Functions: Use functions like COUNT(), SUM(), AVG(), MIN(), and MAX() to summarize and analyze data efficiently.
3. Optimizing Queries: Understand how to write efficient queries and use techniques like indexing and query execution plans for performance optimization.
4. Creating and Managing Databases: Master CREATE, ALTER, and DROP commands for building and maintaining database structures.
5. Understanding Constraints and Keys: Learn the importance of primary keys, foreign keys, unique constraints, and indexes for data integrity.
6. Advanced SQL Techniques: Dive into CASE statements, CTEs (Common Table Expressions), window functions, and stored procedures for more powerful querying.
7. Normalizing Data: Understand database normalization principles and how to design databases to avoid redundancy and ensure consistency.
8. Handling Transactions: Learn how to use BEGIN, COMMIT, and ROLLBACK to manage transactions and ensure data integrity.
9. Staying Updated with SQL Trends: The world of databases evolves—stay informed about new SQL functions, database management systems (DBMS), and best practices.
⏳ With practice, hands-on experience, and a thirst for learning, SQL will empower you to unlock the full potential of data!
You can read detailed article here
I've curated essential SQL Interview Resources👇
https://news.1rj.ru/str/DataSimplifier
Share with credits: https://news.1rj.ru/str/sqlspecialist
Hope it helps :)
It’s the powerful language that helps you manage and manipulate data in databases.
To truly master SQL, focus on these key areas:
0. Understanding the Basics: Get comfortable with SQL syntax, data types, and basic queries like SELECT, INSERT, UPDATE, and DELETE.
1. Mastering Data Retrieval: Learn advanced SELECT statements, including JOINs, GROUP BY, HAVING, and subqueries to retrieve complex datasets.
2. Working with Aggregation Functions: Use functions like COUNT(), SUM(), AVG(), MIN(), and MAX() to summarize and analyze data efficiently.
3. Optimizing Queries: Understand how to write efficient queries and use techniques like indexing and query execution plans for performance optimization.
4. Creating and Managing Databases: Master CREATE, ALTER, and DROP commands for building and maintaining database structures.
5. Understanding Constraints and Keys: Learn the importance of primary keys, foreign keys, unique constraints, and indexes for data integrity.
6. Advanced SQL Techniques: Dive into CASE statements, CTEs (Common Table Expressions), window functions, and stored procedures for more powerful querying.
7. Normalizing Data: Understand database normalization principles and how to design databases to avoid redundancy and ensure consistency.
8. Handling Transactions: Learn how to use BEGIN, COMMIT, and ROLLBACK to manage transactions and ensure data integrity.
9. Staying Updated with SQL Trends: The world of databases evolves—stay informed about new SQL functions, database management systems (DBMS), and best practices.
⏳ With practice, hands-on experience, and a thirst for learning, SQL will empower you to unlock the full potential of data!
You can read detailed article here
I've curated essential SQL Interview Resources👇
https://news.1rj.ru/str/DataSimplifier
Share with credits: https://news.1rj.ru/str/sqlspecialist
Hope it helps :)
❤7
Top 20 AI Concepts You Should Know
1 - Machine Learning: Core algorithms, statistics, and model training techniques.
2 - Deep Learning: Hierarchical neural networks learning complex representations automatically.
3 - Neural Networks: Layered architectures efficiently model nonlinear relationships accurately.
4 - NLP: Techniques to process and understand natural language text.
5 - Computer Vision: Algorithms interpreting and analyzing visual data effectively
6 - Reinforcement Learning: Distributed traffic across multiple servers for reliability.
7 - Generative Models: Creating new data samples using learned data.
8 - LLM: Generates human-like text using massive pre-trained data.
9 - Transformers: Self-attention-based architecture powering modern AI models.
10 - Feature Engineering: Designing informative features to improve model performance significantly.
11 - Supervised Learning: Learns useful representations without labeled data.
12 - Bayesian Learning: Incorporate uncertainty using probabilistic model approaches.
13 - Prompt Engineering: Crafting effective inputs to guide generative model outputs.
14 - AI Agents: Autonomous systems that perceive, decide, and act.
15 - Fine-Tuning Models: Customizes pre-trained models for domain-specific tasks.
16 - Multimodal Models: Processes and generates across multiple data types like images, videos, and text.
17 - Embeddings: Transforms input into machine-readable vector formats.
18 - Vector Search: Finds similar items using dense vector embeddings.
19 - Model Evaluation: Assessing predictive performance using validation techniques.
20 - AI Infrastructure: Deploying scalable systems to support AI operations.
Artificial intelligence Resources: https://whatsapp.com/channel/0029VaoePz73bbV94yTh6V2E
AI Jobs: https://whatsapp.com/channel/0029VaxtmHsLikgJ2VtGbu1R
Hope this helps you ☺️
1 - Machine Learning: Core algorithms, statistics, and model training techniques.
2 - Deep Learning: Hierarchical neural networks learning complex representations automatically.
3 - Neural Networks: Layered architectures efficiently model nonlinear relationships accurately.
4 - NLP: Techniques to process and understand natural language text.
5 - Computer Vision: Algorithms interpreting and analyzing visual data effectively
6 - Reinforcement Learning: Distributed traffic across multiple servers for reliability.
7 - Generative Models: Creating new data samples using learned data.
8 - LLM: Generates human-like text using massive pre-trained data.
9 - Transformers: Self-attention-based architecture powering modern AI models.
10 - Feature Engineering: Designing informative features to improve model performance significantly.
11 - Supervised Learning: Learns useful representations without labeled data.
12 - Bayesian Learning: Incorporate uncertainty using probabilistic model approaches.
13 - Prompt Engineering: Crafting effective inputs to guide generative model outputs.
14 - AI Agents: Autonomous systems that perceive, decide, and act.
15 - Fine-Tuning Models: Customizes pre-trained models for domain-specific tasks.
16 - Multimodal Models: Processes and generates across multiple data types like images, videos, and text.
17 - Embeddings: Transforms input into machine-readable vector formats.
18 - Vector Search: Finds similar items using dense vector embeddings.
19 - Model Evaluation: Assessing predictive performance using validation techniques.
20 - AI Infrastructure: Deploying scalable systems to support AI operations.
Artificial intelligence Resources: https://whatsapp.com/channel/0029VaoePz73bbV94yTh6V2E
AI Jobs: https://whatsapp.com/channel/0029VaxtmHsLikgJ2VtGbu1R
Hope this helps you ☺️
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Learning and Practicing SQL: Resources and Platforms
1. https://sqlbolt.com/
2. https://sqlzoo.net/
3. https://www.codecademy.com/learn/learn-sql
4. https://www.w3schools.com/sql/
5. https://www.hackerrank.com/domains/sql
6. https://www.windowfunctions.com/
7. https://selectstarsql.com/
8. https://quip.com/2gwZArKuWk7W
9. https://leetcode.com/problemset/database/
10. http://thedatamonk.com/
1. https://sqlbolt.com/
2. https://sqlzoo.net/
3. https://www.codecademy.com/learn/learn-sql
4. https://www.w3schools.com/sql/
5. https://www.hackerrank.com/domains/sql
6. https://www.windowfunctions.com/
7. https://selectstarsql.com/
8. https://quip.com/2gwZArKuWk7W
9. https://leetcode.com/problemset/database/
10. http://thedatamonk.com/
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