Hi I have a question about memory management in PostgreSQL. I understand the default on Linux usually is "posix" which creates files in /dev/shm. With the default settings of 128MB for shared_buffers this is the result:
ls -la /dev/shm total 4 drwxrwxrwt 2 root root 60 Feb 17 11:19 . drwxr-xr-x 18 root root 3100 Feb 17 09:36 .. -rw------- 1 postgres postgres 2316 Feb 17 11:19 PostgreSQL.1804289383 Question: Why is this file only 2316 bytes? Switching to sysv (same setting for shared_buffers): ipcs -m ------ Shared Memory Segments -------- key shmid owner perms bytes nattch status 0x0052e2c1 622592 postgres 600 56 5 0x6b8b4567 655361 postgres 600 2316 5 Again 2316 bytes. Why? Is the 56 bytes segment related to Robert's post and only used for determining which processes are attached? http://rhaas.blogspot.com/2012/06/absurd-shared-memory-limits.html Thanks in advance Daniel
