**Performance:**

- One query faster than multiple separate queries

- All conditions processed in single pass

- Simple conditions perform better

- Index columns used in conditions

One query faster than multiple separate queries

All conditions evaluated in single pass

Index columns in conditions

Simple conditions perform better

Avoid deeply nested CASE expressions

Forgetting ELSE 0 causes NULL results

Creating overlapping conditions unintentionally

Using when WHERE would be simpler

Too many conditional aggregates hurts readability

Not handling NULL in conditions explicitly