Mark kirkwood <markir(at)slingshot(dot)co(dot)nz> writes:
> I forgot to mention :
> 1) the test involved usng copy to load the rows !
Still not much help. Was it a single COPY command, or a bunch of them?
The fsync overhead is (and always has been) a per-transaction cost,
so a benchmark that gives you no idea how many transactions were
committed isn't much help. Also, if there was only one transaction
commit in your 5-minute benchmark run, then I can see why fsync would
be pretty irrelevant ... try something with one commit per inserted
row if you want to see a bigger penalty ...
regards, tom lane