On 13 November 2011 00:38, Tom Lane <t...@sss.pgh.pa.us> wrote: > Thom Brown <t...@linux.com> writes: >> But xmin on the file_fdw result is odd. Why are these all over the >> place? > > heap_form_tuple initializes the t_choice fields as though for a tuple > Datum, and file_fdw doesn't change it. > > Just a couple hours ago I was wondering why we create system columns for > foreign tables at all. Is there a reasonable prospect that they'll ever > be useful? I can see potential value in tableoid, but the others seem > pretty dubious --- even if you were fetching from a remote PG server, > the XIDs would not be meaningful within our own environment.
Yes, that's what I was thinking when curiosity led me to have a look at what they contain. As far as I see, they serve no useful function. I didn't bother looking at tableoid as that's generally useful. Is there a cost to having them there? Could there be tools that might break if the columns were no longer available? -- Thom Brown Twitter: @darkixion IRC (freenode): dark_ixion Registered Linux user: #516935 EnterpriseDB UK: http://www.enterprisedb.com The Enterprise PostgreSQL Company -- Sent via pgsql-hackers mailing list (email@example.com) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers