Brandon Craig Rhodes <brandon(at)rhodesmill(dot)org> writes:
> And the disputed point:
> - If the drive holding the WAL fails, then the database engine
> will shut down cleanly by writing everything in RAM out to
> the real database tables, and no data will be lost.
Whoever claimed that has no familiarity with the code at all, and no
understanding of the basic WAL rule: write to the log BEFORE you write
data.
In point of fact, loss of the WAL drive will mean a database PANIC stop
and probably a corrupt data area afterwards, since there'd be no
guarantee that related page updates had all made it to disk.
regards, tom lane