**Performance Tips:**

• Put most common conditions first (short-circuits)

• Avoid complex expressions in WHEN clauses

• Use indexes on columns in WHEN conditions

• Consider computed columns for frequently used CASE

• CASE in WHERE can prevent index usage

Order conditions by frequency (most common first)

Avoid complex expressions in WHEN clauses

CASE in WHERE can prevent index usage

Use indexes on columns in WHEN conditions

Missing ELSE clause returns NULL for unmatched rows

Mixing data types in THEN clauses causes errors

Complex CASE in WHERE prevents index usage

Not considering NULL values in conditions