On Fri, Dec 20, 2013 at 7:51 AM, Andres Freund <and...@2ndquadrant.com> wrote: > On 2013-12-20 07:47:17 -0500, Robert Haas wrote: >> On Fri, Dec 20, 2013 at 7:22 AM, Andres Freund <and...@2ndquadrant.com> >> wrote: >> >> Maybe what we should do is add a function something like >> >> pg_tuple_header(tableoid, ctid) that returns a record, maybe something >> >> like (rawxmin xid, rawxmax xid, rawcid cid, infomask int, infomask2 >> >> int, hoff int). Or perhaps some slightly more cooked version of that >> >> information. And then delete the xmin, xmax, cmin, and cmax system >> >> columns. That'd save significantly on pg_attribute entries while, at >> >> the same time, actually providing more information than we do today. >> > >> > I was wondering whether we couldn't just pass pg_tuple_header() a whole >> > row, instead of having the user manually pass in reloid and ctid. I >> > think that should actually work in the interesting scenarios. >> >> I wondered that, too, but it's not well-defined for all tuples. What >> happens if you pass in constructed tuple rather than an on-disk tuple? > > Those should be discernible I think, t_self/t_tableOid won't be set for > generated tuples.
Hmm. That might work. I think the immediate problem is to decide whether this patch ought to make the xmin column display the result of GetXmin() or GetRawXmin(). Thoughts on that? -- Robert Haas EnterpriseDB: http://www.enterprisedb.com The Enterprise PostgreSQL Company -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
