Simple Anomaly Detection using SQL
Gain insights into using SQL for anomaly detection. Delve into applying mean, standard deviation, and z-score to identify and investigate data anomalies, enhancing your analytical skills.
I am a full stack developer and a team leader with over 15 years of experience. I started as a DBA for data warehouse systems in the pharma and logistics industries. In this role as lead DBA I was in charge of designing database schemas, ETL processes and integrating with various BI tools. I was then promoted to a role of a team leader where I led developers using different technologies such as C++ and C# as well as several DBAs. I’m currently leading the development of a large ticketing and payment system. In my current role I work with large PostgreSQL databases and other open source technologies such as Python, Django and TypeScript. In my spare time I also maintain a popular blog where I share different technical aspects of my work. The blog focuses on optimizing large databases and the challenges of scaling a web app to millions of users.
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What You'll Learn
- Identify anomalies in time-series data by computing mean and standard deviation in SQL
- Calculate z-scores in SQL to flag data points outside defined acceptable ranges
- Tune z-score thresholds in SQL to balance sensitivity and false alerts
- Prepare server log data by filling time gaps with zeros using PostgreSQL functions
- Backtest anomaly detection with SQL window functions and dynamic thresholds on past data
- Reduce repeating alerts by detecting first-occurrence anomalies using SQL thresholds
- Apply weighted mean, median, and MAD in SQL to improve anomaly detection accuracy
Learning Roadmap
1.
Detecting Anomalies
Detecting Anomalies
2.
Analyzing A Server Log
Analyzing A Server Log
3.
Backtesting
Backtesting
5 Lessons
5 Lessons
4.
Improving Accuracy
Improving Accuracy
5 Lessons
5 Lessons
Haki Benita
Haki is a technical lead and a tech blogger interested in databases, web development, software design and performance tuning.
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