In client support of v10 features, use standard schema handling.
Back-patch to v10. This continues the work of commit
080351466c5a669bf35a323bdec9e296330a5dbb.
Discussion: https://postgr.es/m/CAKOSWN=ds66zLw2SqkLTM8wbXFgDbc_OdkmT3dJfPT2mE5kipA@mail.gmail.com