Thread: BUG #15942: not working function pg_stat_file

The following bug has been logged on the website:

Bug reference:      15942
Logged by:          Michal C
Email address:      c_michal@poczta.onet.pl
PostgreSQL version: 11.4
Operating system:   Microsoft Windows [Version 10.0.18362.267]
Description:

Sorry my English is horribile.
my PG version is "PostgreSQL 11.4, compiled by Visual C++ build 1914,
64-bit"

I create 2 GB file:
show data_directory; 
Result: "D:/pg_data"

copy (select

to_char(number,'0.0000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000')
from generate_series(1,1024*1024*2,1) d(number))
to 'D:\pg_data\my_data_01.txt';

and reading information about file:

with files as (select * from pg_ls_dir('.') f(file) where file ilike
'my_data_01.txt')
, files_info as (select file, (pg_stat_file(file)).* from files)
select * from files_info;

and result is:
> ERROR:  could not stat file "my_data_01.txt": Unknown error
> SQL state: XX000

When I run the script on PG 10.9 on the same computer, everything works
fine.

PG Bug reporting form <noreply@postgresql.org> writes:
> I create 2 GB file:
> ...
> (and then pg_stat_file fails on it)

Yeah, this is a known problem on Windows: it provides a stat() function
that fails on large files.  There's been some discussion of how we might
work around that, most recently here:
https://www.postgresql.org/message-id/flat/1803D792815FC24D871C00D17AE95905CF5099%40g01jpexmbkw24

but that hasn't been turned into a patch and you shouldn't
hold your breath waiting for it to happen :-(.  There's probably
no chance that the eventual fix would be safe to back-patch into
existing release branches, either.

So ... we might have a fix for this someday, but probably not soon.

It is annoying that we're just reporting "Unknown error" though.
That could be improved to show something more specific without
a lot of work, I imagine.

            regards, tom lane