**Indexing Strategy:**

- Always index PARTITION BY columns for optimal performance

- Consider composite indexes: (partition_column, order_by_column)

- Use covering indexes to avoid key lookups when possible

**Query Optimization:**

- Partition pruning: Use WHERE clauses to limit partitions processed

- Avoid unnecessary partitions: Don't partition if you need global calculations

- Named windows: Reuse window definitions to improve readability and potentially performance

**Memory Management:**

- Each partition requires memory for intermediate calculations

- Monitor memory usage with large datasets and many partitions

- Consider breaking very large queries into smaller chunks

**Performance Benchmarks:**

- Properly indexed PARTITION BY queries: 85% faster than equivalent self-joins

- Named windows: 15-20% performance improvement in complex queries

- Optimal partition size: 1,000-100,000 rows per partition for best performance

Index PARTITION BY columns in the same order as specified

Fewer, larger partitions generally perform better than many small ones

Use composite indexes: (partition_col, order_by_col) for best performance

Monitor memory usage with large datasets and many partitions

Consider breaking very large queries into smaller, focused chunks

Partition pruning with WHERE clauses can dramatically improve performance

Forgetting to index PARTITION BY columns leads to poor performance

Creating too many tiny partitions increases overhead

Confusing PARTITION BY with GROUP BY - they serve different purposes

Not handling NULL values in partition columns properly

Using PARTITION BY when you actually need GROUP BY (and vice versa)

Ignoring the impact of partition column cardinality on performance