Kyotaro HORIGUCHI <horiguchi.kyot...@lab.ntt.co.jp> writes:
> My point here is that if concurrent deletion can't be perfomed by
> the current implement, this while loop could be removed and
> immediately error out or log a message,
>> if (P_ISDELETED(opaque) || opaque->btpo_next != target)
>> {
>> elog(ERROR, "no left sibling of page %d (concurrent deletion?) in \"%s\"",..
That would certainly break things: there are valid cases for the
loop to need to iterate, specifically where the left sibling got
split before we could acquire lock on it.
> or, the while loop at least should stop before overshooting the
> target.
>> while (P_ISDELETED(opaque) || opaque->btpo_next != target)
>> {
>> /* step right one page */
>> leftsib = opaque->btpo_next;
>> _bt_relbuf(rel, lbuf);
>> if (leftsib == target || leftsib == P_NONE)
>> {
>> elog(ERROR, "no left sibling of page %d (concurrent deletion?) in \"%s\"",..
Huh? Surely that added test condition could never be true because
of the second part of the while() test.
regards, tom lane
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