SQL Server vs. PostgreSQL query optimization: room for improvement?

A detailed comparison of query optimization between SQL Server and PostgreSQL reveals significant performance gaps during database migrations. Key findings include SQL Server's superior parallel execution capabilities using threads versus PostgreSQL's process-based workers, better multi-column selectivity estimation through extended statistics, and advanced parameter value caching. The analysis demonstrates cases where SQL Server achieves 100x speedups through internal parameterization techniques that PostgreSQL lacks, while also highlighting PostgreSQL's strengths and potential improvement areas.