kes-kes@yandex.ru writes:
> Because of type of column of source and destination tables are equal
> postgres does not check actual data so very long data at text field of mysql
> database is inserted into limited field at postgres DB.
I would say this is a bug in mysql_fdw, not Postgres proper. In general
it's the responsibility of an FDW to ensure that data it passes back
meets the constraints of the foreign table declaration.
regards, tom lane
