LINQ Queries for Data Access

Write LINQ queries for a .NET application and explain how you would use them in database access at Balyasny Asset Management.

For this exercise, provide the PostgreSQL equivalent that a LINQ provider should generate. Include active portfolios, current active positions, aggregated gross exposure, and an exposure classification.

Output

1. One row per active portfolio, including portfolios with no qualifying positions.
2. Columns: portfolio_id, portfolio_name, active_position_count, gross_exposure, and exposure_band.
3. Sort by gross_exposure descending, then portfolio_id ascending.