Hi Jakub, The use case that this feature addresses is interesting, but the
proposed implementation feels a bit ad-hoc to us: 1. `COPY ... TO ...`
implies moving data from one place to another. Having a `BLACKHOLE`
destination whose purpose is to check for data corruption seems
counter-intuitive. 2. The argument to `pg_dump --format=...` specifies an
archive format. A `blackhole` archive format and the `archBlackhole` entry
in the `ArchiveFormat` enum in the `pg_dump` code also seem ad-hoc and
counter-intuitive, because nothing is actually being archived. For those
reasons, I don't think `COPY` or `pg_dump` is the right place to support
this use case. Perhaps this needs a new command, but that might
overcomplicate things. In that case, I would prefer to leave things as they
are. Regards, Ahmed & Miłosz