What is Selective Projection?
Fancy term for: Only select columns you actually need.
Example
Bad (gets all 20 columns):
SELECT * FROM products;Good (gets only 3 columns you need):
SELECT product_name, price, stock FROM products;Result: 5x faster!
Why It Matters
Less data = Faster query = Less memory = Better performance
Summary
Always SELECT specific columns Avoid SELECT * in production