> it seems fairly unlikely to me that this would be useful enough to
> justify using up a precious hint bit. The applicability of the hint
> is very short-term --- as soon as the tuple is dead to all transactions,
> it can be marked with the existing LP_DEAD hint bit. And if it's only
> useful fo
Gokulakannan Somasundaram writes:
>While i was studying the unique index checks very closely, i realized
> that what we need is to find out whether the tuple is deleted / not. So say
> a tuple is deleted by a transaction, but it is not dead( because of some
> long running transaction ), still
>
>
> How are you going to unmark the hint bit in case of a rollback?
>
>
Only after you find that the transaction is committed, this hint bit has to
be set. It is equivalent to any other hint bit.
Gokul.
There is no issue with that. Because we are taking a Dirty Snapshot to do
the comparison not the MVCC one. But this should be used only for unique
checks and not for the visibility checks.
Gokul.
On Wed, Mar 24, 2010 at 4:53 PM, Robert Haas wrote:
> On Wed, Mar 24, 2010 at 7:17 AM, Gokulakannan
Hi,
While i was studying the unique index checks very closely, i realized
that what we need is to find out whether the tuple is deleted / not. So say
a tuple is deleted by a transaction, but it is not dead( because of some
long running transaction ), still we can mark a hint bit as deleted and i
