I have been trying to migrate a database hosted in Azure PostgreSQL single server to Flexible server using the managed migration service provided. The migration fails with Foreign Key Constraint Failure Error. On further analysis I found that, on a particular table having a NULL-able column with unique constraint, the rows having NULL values in that column are not migrated. This led to subsequent failures.

Has any one faced this issue? If so how has been resolved?

Additional Info:

Azure internally uses pgcopydb utility

https://learn.microsoft.com/en-us/azure/postgresql/migrate/migration-service/concepts-migration-service-postgresql#additional-information

https://github.com/dimitri/pgcopydb/issues/756