Re: preserving forensic information when we freeze

On Fri, Dec 20, 2013 at 7:22 AM, Andres Freund <andres@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?

-- 
Robert Haas
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