The document summarizes testing performed to evaluate Greenplum, Postgres-XL, and Citus for scaling out PostgreSQL to handle large astronomical datasets. Tests were conducted on ingestion performance, query performance, hardware requirements, and high availability features using real datasets from ESA space missions. Greenplum generally performed best across the tests in terms of speed and scalability. The testing helped identify requirements for distributing the large catalogues and lessons learned for future database architecture planning.