See example project hhh11614_2.zip (please ignore/remove hhh11614.zip) attached:

1. init database (create postgres role, user, pass, db all with same value 'hhh11614', see README.md)
2. change hibernate version in build.gradle to 5.2.8.Final
3. Run JUnit Test -> New entry in hhh11614-table is created, data column references to postgres BLOB-Table
4. change hibernate version in build.gradle to 5.2.9.Final
5. Run JUnit Test -> New entry in hhh11614-table is created, data column contains data in place instead of foreign key with 5.2.8.Final

data created with 5.2.8 can not be read with 5.2.9
data created with 5.2.8 can be read with 5.2.8
data created with 5.2.9 can be read with 5.2.9