SHMMAX - Maximum size of shared memory segment (bytes)at least several megabytes (see text)
SHMMIN - Minimum size of shared memory segment (bytes)1
SHMALL - Total amount of shared memory available (bytes or pages)if bytes, same as SHMMAX; if pages, ceil(SHMMAX/PAGE_SIZE)
SHMSEG - Maximum number of shared memory segments per processonly 1 segment is needed, but the default is much higher
SHMMNI - Maximum number of shared memory segments system-widelike SHMSEG plus room for other applications
SEMMNI - Maximum number of semaphore identifiers (i.e., sets)at least ceil((max_connections + autovacuum_max_workers + 4) / 16)
SEMMNS - Maximum number of semaphores system-wideceil((max_connections + autovacuum_max_workers + 4) / 16) * 17 plus room for other applications
SEMMSL - Maximum number of semaphores per setat least 17
SEMMAP - Number of entries in semaphore mapsee text
SEMVMX - Maximum value of semaphoreat least 1000 (The default is often 32767; do not change unless necessary