Re: POC: Lock updated tuples in tuple_update() and tuple_delete()

Hi Alexander,

> Thoughts and feedback are welcome.

I took some preliminary look at the patch. I'm going to need more time
to meditate on the proposed changes and to figure out the performance
impact.

So far I just wanted to let you know that the patch applied OK for me
and passed all the tests. The `else` branch here seems to be redundant
here:

+ if (!updated)
+ {
+ /* Should not encounter speculative tuple on recheck */
+ Assert(!HeapTupleHeaderIsSpeculative(tuple->t_data));
- ReleaseBuffer(buffer);
+ ReleaseBuffer(buffer);
+ }
+ else
+ {
+ updated = false;
+ }

Also I wish there were a little bit more comments since some of the
proposed changes are not that straightforward.

--
Best regards,
Aleksander Alekseev