Re: pg_checksums (or checksums in general) vs tableam

On Wed, Jul 10, 2019 at 09:19:03AM -0700, Andres Freund wrote:
> On July 10, 2019 9:12:18 AM PDT, Magnus Hagander <magnus(at)hagander(dot)net> wrote:
>> That would be fine, if we actually knew. Should we (or have we already?)
>> defined a rule that they are not allowed to use the same naming standard
>> unless they have the same type of header?
>
> No, don't think we have already. There's the related problem of
> what to include in base backups, too.

Yes. This one needs a careful design and I am not sure exactly what
that would be. At least one new callback would be needed, called from
basebackup.c to decide if a given file should be backed up or not
based on a path. But then how do you make sure that a path applies to
one table AM or another, by using a regex given by all table AMs to
see if there is a match? How do we handle conflicts? I am not sure
either that it is a good design to restrict table AMs to have a given
format for paths as that actually limits the possibilities when it
comes to split across data across multiple files for attributes and/or
tablespaces. (I am a pessimistic guy by nature.)
--
Michael