> Vlad,
>
>> PS Snapshot (concurrency) transaction guarantees that once read record
>> could be read again and will be the same. So, in theory, we can just
>> re-read same data page when looking for next record.
>
> Why "in theory"?
Because i want to be careful and don't want to make too early conclusions :)
This (raw) idea should be considered from the all possible points of view
and, ideally,
we need to find a way to make same optimisation for every kind of transaction.
>
> I don't see how the DP could change for the purposes of the next record for
> Snapshot transactions.
>
> Yes, the additional versions of the next record could be posted to the DP in
> the cache page (marking
> changes or deletions) but the "existence" of the record on the DP can't
> change within the snapshot.
> Only if the new record changes have "overflowed" to other DPs would other
> pages need to be loaded.
>
>
> It would seem that a significant performance improvement could be yielded by
> changing the current functionality.
It could be not so significant, especially with shared cache in mind :)
Regards,
Vlad
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