Re: [PATCH v1] pg_ls_tmpdir to show directories

On Tue, Mar 03, 2020 at 02:51:54PM -0500, David Steele wrote:
> Hi Fabien,
>
> On 1/16/20 9:38 AM, Justin Pryzby wrote:
> >On Thu, Jan 16, 2020 at 09:34:32AM +0100, Fabien COELHO wrote:
> >>Also, I'm not fully sure why ".*" files should be skipped, maybe it should
> >>be an option? Or the user can filter it with SQL if it does not want them?
> >
> >I think if someone wants the full generality, they can do this:
> >
> >postgres=# SELECT name, s.size, s.modification, s.isdir FROM (SELECT 'base/pgsql_tmp'p)p, pg_ls_dir(p)name, pg_stat_file(p||'/'||name)s;
> > name | size | modification | isdir
> >------+------+------------------------+-------
> > .foo | 4096 | 2020-01-16 08:57:04-05 | t
> >
> >In my mind, pg_ls_tmpdir() is for showing tmpfiles, not just a shortcut to
> >SELECT pg_ls_dir((SELECT 'base/pgsql_tmp'p)); -- or, for all tablespaces:
> >WITH x AS (SELECT format('/PG_%s_%s', split_part(current_setting('server_version'), '.', 1), catalog_version_no) suffix FROM pg_control_system()), y AS (SELECT a, pg_ls_dir(a) AS d FROM (SELECT DISTINCT COALESCE(NULLIF(pg_tablespace_location(oid),'')||suffix, 'base') a FROM pg_tablespace,x)a) SELECT a, pg_ls_dir(a||'/pgsql_tmp') FROM y WHERE d='pgsql_tmp';
> >
> >I think changing dotfiles is topic for another patch.
> >That would also affect pg_ls_dir, and everything else that uses the backing
> >function pg_ls_dir_files_recurse. I'd have to ask why not also show . and .. ?
> >
> >(In fact, if I were to change anything, I would propose to limit pg_ls_tmpdir()
> >to files matching PG_TEMP_FILE_PREFIX).
>
> We seem to be at an impasse on this patch. What do you think of Justin's
> comments here?

Actually, I found Fabien's comment regarding extensions use of tmp dir to be
convincing. And I'm willing to update the patch to use a stack to show
arbitrarily-deep files/dirs rather than just one level deep (as used for shared
filesets in core postgres).

But I don't think it makes sense to go through more implementation/review
cycles without some agreement from a larger group regarding the
desired/intended interface. Should there be a column for "parent dir" ? Or a
column for "is_dir" ? Should dirs be shown at all, or only files ?

--
Justin