Re: Custom/Foreign-Join-APIs (Re: [v9.5] Custom Plan API)

On Mon, Mar 9, 2015 at 11:18 PM, Kouhei Kaigai <kaigai@ak.jp.nec.com> wrote:
> The attached patch integrates a suggestion from Ashutosh Bapat.
> It allows to track set of relations involved in a join, but
> replaced by foreign-/custom-scan. It enables to make correct
> EXPLAIN output, if FDW/CSP driver makes human readable symbols
> using deparse_expression() or others.
>
> Differences from v7 is identical with what I posted on the
> join push-down support thread.

I took a look at this patch today and noticed that it incorporates not
only documentation for the new functionality it adds, but also for the
custom-scan functionality whose documentation I previously excluded
from commit on the grounds that it needed more work, especially to
improve the English.  That decision was not popular at the time, and I
think we need to remedy it before going further with this.  I had
hoped that someone else would care about this work enough to help with
the documentation, but it seems not, so today I went through the
documentation in this patch, excluded all of the stuff specific to
custom joins, and heavily edited the rest.  The result is attached.

If there are no objections, I'll commit this; then, someone can rebase
this patch over these changes and we can proceed from there.

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