Re: HOT updates & REDIRECT line pointers

On Thu, Mar 22, 2012 at 1:28 AM, Robert Haas <robertmhaas@gmail.com> wrote:
> On Wed, Mar 21, 2012 at 9:22 PM, Tom Lane <tgl@sss.pgh.pa.us> wrote:
>>> It strikes me that it likely wouldn't be any
>>> worse than, oh, say, flipping the default value of
>>> standard_conforming_strings,
>>
>> Really?  It's taking away functionality and not supplying any substitute
>> (or at least you did not propose any).  In fact, you didn't even suggest
>> exactly how you propose to not break joined UPDATE/DELETE.
>
> Oh, hmm, interesting.  I had been thinking that you were talking about
> a case where *user code* was relying on the semantics of the TID,
> which has always struck me as an implementation detail that users
> probably shouldn't get too attached to.  But now I see that you're
> talking about something much more basic - the fundamental
> implementation of UPDATE and DELETE relies on the TID not changing
> under them.  That pretty much kills this idea dead in the water.

Surely it just stops you using that idea 100% of the time. I don't see
why you can't have this co-exist with the current mechanism. So it
doesn't kill it for the common case.

But would the idea deliver much value? Is line pointer bloat a
problem? (I have no idea if it is/is not)

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