Frank, Why doesn't the shared OID space make cross-database queries possible? SQL Server does it, so the idea isn't that far-fetched.
On Fri, May 15, 2026 at 6:18 PM Frank Heikens <[email protected]> wrote: > > Hi Shivam, > > Thank you for your feedback. > > One important difference is terminology. > > In MySQL, CREATE DATABASE and CREATE SCHEMA are essentially the same > command, so what MySQL calls a “database” is effectively a schema > (namespace). > > PostgreSQL also supports querying across schemas natively, so the same > functionality is already available when the objects are in the same > PostgreSQL database. > > In PostgreSQL, a database is a true isolation boundary with its own > catalogs and connection context. Because of this design, direct joins > across databases are not supported. When this is required, postgres_fdw is > the recommended solution. > > So for most MySQL users, the equivalent approach in PostgreSQL is to use > multiple schemas within a single database rather than multiple databases. > > Best regards, > Frank Heikens > > > > > On May 15, 2026, at 3:06 PM, Shivam Pandey <[email protected]> > wrote: > > > > > > Hello PostgreSQL Team, > > > > I would like to share feedback from a developer perspective regarding > cross-database querying in PostgreSQL. > > > > One feature that many developers appreciate in MySQL is the ability to > directly query and join tables across multiple databases within the same > server instance. This approach becomes very useful in real-world situations > where applications need to access shared or distributed data quickly and > efficiently. > > > > In PostgreSQL, achieving similar functionality often requires additional > setup using extensions such as postgres_fdw or dblink. While these > solutions are powerful and architecturally clean, they can feel complex for > developers who are building applications rapidly or migrating from systems > like MySQL. > > > > It would be valuable if PostgreSQL could provide a more > developer-friendly and simplified native approach for cross-database > querying while still maintaining PostgreSQL’s strong isolation and security > principles. > > > > Possible improvements could include: > > > > 1)Simpler syntax for cross-database joins > > 2) Easier configuration for trusted local databases > > 3) Built-in lightweight federation support > > 4) Better onboarding documentation for multi-database use cases > > > > PostgreSQL is already one of the most powerful and respected databases > in the industry. Enhancing developer convenience in this area could make > adoption even smoother for many teams. > > > > Thank you for your incredible work and continuous innovation. > > > > Best Regards, > > Shivam Pandey > -- Death to <Redacted>, and butter sauce. Don't boil me, I'm still alive. <Redacted> lobster!
