Re: [PATCH] Test coverage for pg_clear_attribute_stats() null arguments

> Could you expand the patch to do more of this stuff, please?

v2 attached. On top of the four null arguments it covers a missing
schema, relation and column, a system column, and a sequence and a view
for the relkind rejection.

For inherited I used a functional case rather than an error one: plant an
inherited and a non-inherited row for one column, clear the inherited
one, and check that the other survives.

Thanks,
Shihao