Direct I/O
A storage method by which the application writes directly to the storage device
Direct I/O (direct input/output) is a storage method by which the application writes directly to the storage device, bypassing the operating system read and write caches.
Direct I/O is not supported by PostgreSQL.
For a overview of historical discussions on this (controversial) subject, see:
- Why we are going to have to go DirectIO (thread on pgsql-hackers)
- Thread summary: the Linux kernel and PostgreSQL (lwn.net)
Useful links
- Direct I/O - RedHat documentation