Pavan Deolasee wrote:
On 2/11/07, Hannu Krosing <[EMAIL PROTECTED]> wrote:
Ühel kenal päeval, P, 2007-02-11 kell 12:35, kirjutas Tom Lane:
> Hannu Krosing <[EMAIL PROTECTED]> writes:
> > What if we would just reuse the root tuple directly instead of
turning
> > it into a stub ?
> > This would create a cycle of ctid pointers, which changes the lookup
> > process from 'follow ctid chaint until the end' to 'follow the tid
chain
> > until you reach the start'.
>
> How do you know which one is newest?
By xmin,cmin of course .
This sounds interesting. But we might have trouble supporting HOT-update
when
tuple length changes. May be we can release the space consumed by the dead
root
tuple and have fresh allocation if the tuple length increases.
I don't see a problem with length changes. We're free to rearrange data
on the page whenever we can acquire the vacuum lock.
--
Heikki Linnakangas
EnterpriseDB http://www.enterprisedb.com
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