Re: TABLESPACE and directory for Foreign tables?

On 05/05/2014 10:53 AM, Tom Lane wrote:
> Josh Berkus <josh@agliodbs.com> writes:
>> I'm working with the cstore_fdw project, which has an interesting
>> property for an FDW: the FDW itself creates the files which make up the
>> database.   This raises a couple of questions:
>
>> 1) Do we want to establish a standard directory for FDWs which create
>> files, such as $PGDATA/base/{database-oid}/fdw/ ?  Or would we want to
>> leave it up to each FDW to decide?
>
> I think we ought to vigorously discourage FDWs from storing any files
> inside $PGDATA.  This cannot lead to anything except grief.  Just for
> starters, what will operations such as pg_basebackup do with them?

That was one advantage to putting them in PGDATA; you get a copy of the
files with pg_basebackup.  Of course, they don't replicate after that,
but they potentially could, in the future, with Logical Streaming
Replication.