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

From: Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us>
To: tomas(dot)dalebjork(at)gmail(dot)com
Cc: pgsql-bugs(at)lists(dot)postgresql(dot)org
Subject: Re: BUG #16842: pg_dump uses seek calls on pipe files: suggesting adding a flag to disable seek calls
Date: 2021-01-28 15:32:46
Message-ID: 2546666.1611847966@sss.pgh.pa.us
Views: Raw Message | Whole Thread | Download mbox | Resend email
Thread:
Lists: pgsql-bugs

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

In response to

Responses

Browse pgsql-bugs by date

  From Date Subject
Next Message Tom Lane 2021-01-28 15:34:46 Re: BUG #16843: pg_upgrade from 12.5 to 13.1 with extension plperlu failed
Previous Message PG Bug reporting form 2021-01-28 13:16:32 BUG #16844: Relation mapping file "global/pg_filenode.map" contains invalid data