From: Davlet Panech <dpanech@gmail.com>
To: pgsql-admin@lists.postgresql.org
Subject: Re: Abnormally high memory usage/OOM triggered
Date: Thu, 18 Jan 2018 12:13:33 -0500
Message-ID: <15a90b55-5151-ce22-16ee-7ff883e5eb97@gmail.com> (raw)
In-Reply-To: <5E0AB8DB-F13B-41BF-843A-FE64FBE9C097@elevated-dev.com>
References: <4d52fee7-73ba-16a9-9c27-8ae5107ee6ae@gmail.com>
<5E0AB8DB-F13B-41BF-843A-FE64FBE9C097@elevated-dev.com>
On 1/17/2018 5:57 PM, scott ribe wrote:
> On Jan 17, 2018, at 2:57 PM, Davlet Panech <dpanech@gmail.com> wrote:
>>
>> Does my configuration look reasonable? I just don't understand how it could possibly use up 19 GB of memory based on the configuration below. Is there a memory leak in there somewhere?
>
> It does seem awfully high, but... An update can involve a join across multiple tables. Or an update can run a trigger which can cascade. Either of those could result in an "accidental cross product" join, which can always blow up memory.
There must be a way to put an upper limit on memory even for such cases.
I was under the impression that parameters such as "work_mem" serve that
purpose, is that not the case? So an "accidental cross product" join's
memory usage is unbounded? It can't be... could somebody confirm this
please?
Thanks,
D.
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Cc: dpanech@gmail.com, pgsql-admin@lists.postgresql.org
Subject: Re: Abnormally high memory usage/OOM triggered
In-Reply-To: <15a90b55-5151-ce22-16ee-7ff883e5eb97@gmail.com>
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