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
* Konstantin Malanchev <hombit@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/shmis like virtual memory or RAM disk.Increase the RAM.Jean