POSTGRESQL TEAMS DISABLE MEMORY OVERCOMMIT

Memory overcommit allows Linux systems to allocate more RAM than physically available, relying on the assumption that not all processes will use their full allocation simultaneously. When memory runs short, the OOM killer terminates processes to free resources. For PostgreSQL, this creates a dangerous scenario. The OOM killer may terminate a critical backend process mid-transaction, causing data corruption, connection drops, and operational disruption. Disabling overcommit via `vm.overcommit_memory=2` forces the kernel to deny memory allocation requests that exceed available RAM. While this wastes some memory capacity—allocations may fail even when physical memory exists—it prevents unexpected process termination. Alternatively, `vm.overcommit_memory=1` permits overcommit but with predictable behavior. Teams using strict settings report improved stability in production environments at the cost of lower memory utilization rates. The debate reflects a broader tension in infrastructure: efficiency versus predictability. For stateful services like databases, predictability typically wins.