I would like to use postgresql's unlogged tables on an embedded system to avoid frequent writes to flash memory. While documentation clearly states that unlogged tables don't have to go through the WAL,
That's not really true. There are no per-row WAL records. There is still a per-transaction WAL record, the commit record. If you only care about the timing of the WAL and not the volume, changing to unlogged will not make a difference. (These commit-only records are automatically dealt with asynchronously, even if synchronous-commit is on.)
