Hello Jean, I have 8 GB RAM and /dev/shm size is 4GB, and there is no significant memory usage by other system processes. I surprised that Postgres uses more space in /dev/shm than sharred_buffers parameter allows, probably I don't understand what this parameter means.
I have no opportunity to enlarge total RAM and probably this query requires too much RAM to execute. Should Postgres just use HDD as temporary storage in this case? Konstantin > On 9 Jul 2019, at 12:53, Jean Louis <bugs@gnu.support> wrote: > > * Konstantin Malanchev <hom...@gmail.com <mailto:hom...@gmail.com>> > [2019-07-09 11:51]: >> Hello, >> >> I'm running PostgreSQL 11.4 on Linux 4.12.14 and I see the following issue >> while executing single one query: >> ERROR: could not resize shared >> memory segment "/PostgreSQL.1596105766" to 536870912 bytes: No space left on >> device >> >> In my postgresql.conf I set sharred_buffers=256MB, I see that it is applied: >> SHOW shared_buffers; >> shared_buffers >> ---------------- >> 256MB >> >> At the same time during the query execution, I see a lot of files in >> /dev/shm with the total size more than 256MB >> >> ls -lh /dev/shm >> >> How can I configure limit for total shared memory size? > > The limit is mostly set by the memory, as /dev/shm > is like virtual memory or RAM disk. > > Increase the RAM. > > Jean
