Re: [HACKERS] Possibly too stringent Assert() in b-tree code - Mailing list pgsql-hackers

From Tom Lane
Subject Re: [HACKERS] Possibly too stringent Assert() in b-tree code
Date
Msg-id 3390.1531178982@sss.pgh.pa.us
Whole thread Raw
In response to Re: [HACKERS] Possibly too stringent Assert() in b-tree code  (Kyotaro HORIGUCHI <horiguchi.kyotaro@lab.ntt.co.jp>)
List pgsql-hackers
Kyotaro HORIGUCHI <horiguchi.kyotaro@lab.ntt.co.jp> writes:
> At Mon, 26 Sep 2016 09:12:04 +0530, Amit Kapila <amit.kapila16@gmail.com> wrote in
<CAA4eK1K5YyDmndko0zzW6WNCN_DGFVHa6DCYcyuvkBWTH5+nUQ@mail.gmail.com>
>>> It seems to me that we do take actions for conflict resolution during
>>> the page deletion (that looks to be covered by XLOG_HEAP2_CLEANUP_INFO
>>> which we emit in vacuum), but not sure if that is sufficient.
>>> Consider a case where the new transaction is started on standby after
>>
>> Here by new transaction, I intend to say some newer snapshot with
>> valid MyPgXact->xmin.

> I agree to the diagnosis. So the WAL record is not necessary if
> it is a new page since no one cannot be grabbing it.

Thanks for reviving this thread and reviewing the problem.
I pushed the patch now with some more work on the comments.

            regards, tom lane


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