If you care about performance, they are required. https://dev.to/jbranchaud/beware-the-missing-foreign-key-index-a-postgres-performance-gotcha-3d5i https://dev

If you care about performance, they are required. https://dev.to/jbranchaud/beware-the-missing-foreign-key-index-a-postgres-performance-gotcha-3d5i https://dev.to/jbranchaud/beware-the-missing-foreign-key-ind... Again, another thing we learnt the hard way. All FKs now require a index for us.