Horton

Re: OOM in spgist insert

Pavel Borisov <pashkin.elfe@gmail.com>

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From: Pavel Borisov <pashkin.elfe@gmail.com>
To: Dilip Kumar <dilipbalaut@gmail.com>
Cc: PostgreSQL Hackers <pgsql-hackers@lists.postgresql.org>
Date: 2021-05-12T08:39:04Z
Lists: pgsql-hackers

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ср, 12 мая 2021 г. в 12:36, Dilip Kumar <dilipbalaut@gmail.com>:

> On Wed, 12 May 2021 at 1:43 PM, Pavel Borisov <pashkin.elfe@gmail.com>
> wrote:
>
>> ср, 12 мая 2021 г. в 11:09, Dilip Kumar <dilipbalaut@gmail.com>:
>>
>>> While testing something on spgist I found that at certain point while
>>> inserting in spgist it is going for doPickSplit, but even after split
>>> is is not able to find a place to insert a tuple and it keeping going
>>> in that loop infinitely it seems and finally error out with OOM
>>> because in this loop we are continuously allocating memory for the
>>> tuple in temp context but since we are never coming out of the loop it
>>> is erroring out with OOM.
>>>
>>> My first idea is that this is the case when index tuple doesn't fit into
>> one index page. As INCLUDED columns are added as is the tuple can not be
>> made shorter by prefix-stripping. Seems we should check every index tuple
>> length to fit the page before its insertion.
>>
>
> Thanks for looking into this.
>
> Will see the code little bit later.
>>
>
> Ok
>
PFA v1 patch. Does this help?


-- 
Best regards,
Pavel Borisov

Postgres Professional: http://postgrespro.com <http://www.postgrespro.com>

Commits

  1. Prevent infinite insertion loops in spgdoinsert().

  2. Fix query-cancel handling in spgdoinsert().

  3. Refactor CHECK_FOR_INTERRUPTS() to add flexibility.