Greg Stark <gsstark@mit.edu> writes:
> The error means that your system does not support the system interface
> we need to support prefetching. In that case effective_io_concurrency
> will be a read-only parameter set to 0 and any attempt to set it will
> result in an error.
I wonder whether it would be better to have it still be a read-write
parameter, but with min/max values equal to zero. All the other cases
where we have read-only parameters, they're *always* read-only. It
seems a bit odd that this one is platform-specific not only as to the
allowed range but whether it can be assigned at all.
regards, tom lane