Re: [Patch] Make pg_checksums skip foreign tablespace directories

On 2/21/20 1:36 AM, Michael Paquier wrote:
 > On Thu, Feb 20, 2020 at 05:38:15PM +0100, Bernd Helmle wrote:
 >> So i propose a different approach like the attached patch tries to
 >> implement: instead of just blindly iterating over directory contents
 >> and filter them out, reference the tablespace location and
 >> TABLESPACE_VERSION_DIRECTORY directly. This is done by a new function
 >> scan_tablespaces() which is specialized in just follow the
 >> symlinks/junctions in pg_tblspc and call scan_directory() with just
 >> what it has found there. It will also honour directories, just in case
 >> an experienced DBA has copied over the tablespace into pg_tblspc
 >> directly.
 >
 > +       if (S_ISREG(st.st_mode))
 > +       {
 > +           pg_log_debug("ignoring file %s in pg_tblspc", de->d_name);
 > +           continue;
 > +       }
 > We don't do that for the normal directory scan path, so it does not
 > strike me as a good idea on consistency ground.  As a whole, I don't
 > see much point in having a separate routine which is just roughly a
 > duplicate of scan_directory(), and I think that we had better just add
 > the check looking for matches with TABLESPACE_VERSION_DIRECTORY
 > directly when having a directory, if subdir is "pg_tblspc".  That
 > also makes the patch much shorter.

+1.  This is roughly what pg_basebackup does and it seems simpler to me.

Regards,
-- 
-David
david@pgmasters.net