Re: Query error: could not resize shared memory segment

On Wed, Jan 3, 2018 at 5:05 PM, Thuc Nguyen Canh
<thucnguyencanh(at)gmail(dot)com> wrote:
> The dynamic_shared_memory_type is posix, the before and after values for
> work_mem are ~41MB and ~64MB.
> I'm using a Digital Ocean vps of 16RAM 8 Cores.
> For more information, I managed to reproduce this issue on a fresh vps after
> I changed the random_page_cost from 4.0 to 1.1. So that said, I did reduce
> the random_page_cost to 1.1, in order to optimize postgresql performance on
> SSD (DO uses SSD) and got this issue.

So you have 16GB of RAM and here we're failing to posix_fallocate()
50MB (actually we can't tell if it's the ftruncate() or
posix_fallocate() call that failed, but the latter seems more likely
since the former just creates a big hole in the underlying tmpfs
file). Can you share the query plan (EXPLAIN SELECT ...)?

--
Thomas Munro
http://www.enterprisedb.com