Migrate SQL Server multi-result-set procedures to PostgreSQL

This article explains how to migrate SQL Server multi-result-set stored procedures to PostgreSQL, which doesn't natively support returning multiple independent result sets from a single procedure call.

• SQL Server procedures return multiple result sets via separate SELECT statements; PostgreSQL requires alternative patterns
• Temporary tables approach: procedure creates session-scoped tables, caller reads them sequentially in same transaction
• JSON aggregation approach: function returns all result sets in single structured JSON document with named arrays
• Temporary tables suit large result sets and row-by-row retrieval; JSON aggregation suits bounded results and single-response patterns
• Performance testing shows JSON faster at 100-1,000 rows per result set; temporary tables 31% faster at 10,000 rows
• Includes .NET/Npgsql code examples, validation strategies, and operational considerations for transactions and connection pooling

Choose the approach based on result-set size, retrieval patterns, and application requirements, then validate functional equivalence before production deployment.