Re: Postgres_fdw join pushdown - wrong results with whole-row reference

On 2016/06/27 18:56, Ashutosh Bapat wrote:

On Mon, Jun 27, 2016 at 3:06 PM, Etsuro Fujita
<fujita.etsuro@lab.ntt.co.jp <mailto:fujita.etsuro@lab.ntt.co.jp>> wrote:

    I found another bug in error handling of whole-row references in
    join pushdown; conversion_error_callback fails to take into account
    that get_relid_attribute_name(Oid relid, AttrNumber attnum) can't
    handle whole-row references (ie, attnum=0), in which case that would
    cause cache lookup errors.  Attached is a small patch to address
    this issue.

Do you have any testcase reproducing the bug here? It would be good to
include that test in the regression.

Done.

There is a always a possibility that a user would create a table (which
can be used as target for the foreign table) with column named
'wholerow', in which case s/he will get confused with this error message.

By grepping I found that there are error messages that use "whole-row table reference", "whole-row reference",

or "wholerow", so the use of "wholerow" seems to me reasonable.  (And IMO I think "wholerow" would most likely fit into that errcontext().)