Re: pgsql: Reduce spurious Hot Standby conflicts from never-visible records

Simon Riggs <simon(at)2ndQuadrant(dot)com> writes:
> Reduce spurious Hot Standby conflicts from never-visible records.
> Hot Standby conflicts only with tuples that were visible at
> some point. So ignore tuples from aborted transactions or for
> tuples updated/deleted during the inserting transaction when
> generating the conflict transaction ids.

> Following detailed analysis and test case by Noah Misch.
> Original report covered btree delete records, correctly observed
> by Heikki Linnakangas that this applies to other cases also.
> Fix covers all sources of cleanup records via common code.
> Includes additional fix compared to commit on HEAD

ISTM HeapTupleHeaderAdvanceLatestRemovedXid is still pretty broken,
in that it's examining xmax without having checked that xmax is (a)
valid or (b) a lock rather than a deletion xmax.

regards, tom lane