Re: BUG #15333: pg_dump error on large table -- "pg_dump: could not stat file...Unknown error"

On Fri, Aug 17, 2018 at 10:53:11AM -0400, Tom Lane wrote:
> Mark Lai <mark(dot)lai(at)integrafec(dot)com> writes:
>> I ran the dump on the large table with no jobs flag and got the same error.
>> ...
>> The dump was successful on a small table.
>
> Weird indeed. Can any Windows developers reproduce this and poke into it?
>
> I have a sneaking suspicion that this is related to Windows' known issues
> with concurrently-opened files, but it's pretty hard to see why there
> would be a dependency on the size of the file.

When it comes to pg_dump, the error message reported seems to come from
src/common/file_utils.c, in walkdir when processing links. On Windows
we map lstat() to stat(), which is itself pgwin32_safestat().

If you use pg_dump --no-sync, the error could be bypassed but that's
hardly a fix. That could be a failure on GetFileAttributeEx(). Which
file system are you using?
--
Michael