On 4 August 2016 at 18:05, Bruce Momjian <bruce@momjian.us> wrote:
>> Approach 2 seems more reasonable and simple.
>>
>> There are only 2 bits for lp_flags and all combinations are already used. But
>> for LP_REDIRECT root line pointer, we could use the lp_len field to store this
>> special flag, which is not used for LP_REDIRECT line pointers. So we are able
>> to mark the root line pointer.
>
> Uh, as I understand it, we only use LP_REDIRECT when we have _removed_
> the tuple that the ctid was pointing to, but it seems you would need to
> set HEAP_RECHECK_REQUIRED earlier than that.
Hmm. Mostly there will be one, so this is just for the first update
after any VACUUM.
Adding a new linepointer just to hold this seems kludgy and could mean
we run out of linepointers.
--
Simon Riggs http://www.2ndQuadrant.com/
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