**Performance Tips:**

- String aggregation can be memory-intensive

- Limit result length when possible

- Index columns used in ORDER BY

- Consider performance impact on large groups

String aggregation memory-intensive on large groups

Index columns in ORDER BY clause

Limit result length when possible

Consider alternative denormalization strategies

Test performance with realistic data volumes

Forgetting database-specific syntax differences

Not ordering values leading to inconsistent results

Exceeding maximum string length limits

Not handling NULL values appropriately

Using on very large groups without testing