Re: BUG #16842: pg_dump uses seek calls on pipe files: suggesting adding a flag to disable seek calls

thanks for the feedback Tom

is the seek enabled only if —format=custom
or is it enabled regardless of which flag used?

regards Tomas

Sent from my iPhone

> On 28 Jan 2021, at 16:32, Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us> wrote:
>
> PG Bug reporting form <noreply(at)postgresql(dot)org> writes:
>> It would be good to add a flag to disable this feature, as some devices does
>> not support seek calls, for example streaming devices such as a tape
>> drive.
>
> That seems like an extremely niche use-case, so I'm unexcited about adding
> a switch for it. You can get the same results with a pipe, as your quoted
> response from Red Hat support suggests.
>
> Note that disabling seeking is not all that desirable in the first place,
> as it will result (for -Fc output) in a dump file that is significantly
> restrictive to restore performance, due to lack of data offset pointers.
> You might really be best advised to rethink whether you want to write
> directly to an unseekable device, rather than to a temp file you transfer
> to tape later.
>
> regards, tom lane