exploratory data analysis (EDA)
Back to DuckDB Data Engineering Glossary
Exploratory Data Analysis (EDA) is a crucial approach in data science that involves examining and visualizing datasets to uncover patterns, anomalies, and relationships. This process, often performed before formal modeling or hypothesis testing, helps analysts understand the underlying structure of their data. EDA typically involves using statistical summaries and graphical representations to identify trends, outliers, and potential correlations between variables. Tools like Pandas for Python or ggplot2 for R are commonly used for EDA, allowing data professionals to create quick visualizations and perform basic statistical analyses. In the context of DuckDB, you might perform EDA using SQL queries to summarize data, for example:
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-- Get basic statistics for a numeric column
SELECT
AVG(column_name) as mean,
MEDIAN(column_name) as median,
MIN(column_name) as min,
MAX(column_name) as max,
STDDEV(column_name) as std_dev
FROM table_name;
-- Count unique values in a categorical column
SELECT
category_column,
COUNT(*) as frequency
FROM table_name
GROUP BY category_column
ORDER BY frequency DESC;
These queries help analysts quickly gain insights into their data's distribution and composition, forming the foundation for more advanced analyses or machine learning models.