Re: foreign data wrapper option manipulation during Create foreign table time?

On Tue, Oct 28, 2014 at 5:26 PM, Demai Ni <nidmgg(at)gmail(dot)com> wrote:
> I am looking for a couple pointers here about fdw, and how to change the
> option values during CREATE table time.
>
> I am using postgres-xc-1.2.1 right now. For example, it contains file_fdw,
> whose create-table-stmt looks like:
> CREATE FOREIGN TABLE t1(....)
> SERVER file_server
> OPTIONS(format 'text',filename 'testing.txt');
>
> I would like to replace the 'testing.txt' with absolute path like
> '/user/testor1/testing.txt', and make sure the new value is saved in
> pg_foreign_table; the file_fdw_validator is used to validate the options,
> but is there a way to replace the optionValue here? And get the new value
> stored in pg_foreign_table?
>
> Thanks
>
> BTW, in my real use case, I am trying to interpret a hdfs file and would
> need to save some hostname/port information in the option value, which not
> necessary specified by user.

I don't think there's going to be a clean way to do this. The
intention of the system is that the user-provided options are simply
stored, not that the FDW author is going to use the options list to
store their own bits and pieces.

--
Robert Haas
EnterpriseDB: http://www.enterprisedb.com
The Enterprise PostgreSQL Company