use_remote_explain missing in docs of postgres_fdw

Started by Michael Paquierabout 13 years ago4 messageshackers
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#1Michael Paquier
michael@paquier.xyz

Hi all,

While testing a bit this feature, I noticed that use_remote_explain is
available in the list of options for FOREIGN TABLE and SERVER but this is
not specified in the docs:
http://www.postgresql.org/docs/devel/static/postgres-fdw.html

postgres=# CREATE FOREIGN TABLE foo (a int, b int) server postgres_server
options (table_name 'aa', foo 'true');
ERROR: invalid option "foo"
HINT: Valid options in this context are: schema_name, table_name,
use_remote_explain

Regards,
--
Michael

#2Tom Lane
tgl@sss.pgh.pa.us
In reply to: Michael Paquier (#1)
Re: use_remote_explain missing in docs of postgres_fdw

Michael Paquier <michael.paquier@gmail.com> writes:

While testing a bit this feature, I noticed that use_remote_explain is
available in the list of options for FOREIGN TABLE and SERVER but this is
not specified in the docs:
http://www.postgresql.org/docs/devel/static/postgres-fdw.html

Wups ... for some reason it's "use_remote_estimate" in the docs. Thinko
on my part probably --- although on reflection, maybe that's a better
name anyway?

regards, tom lane

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#3Michael Paquier
michael@paquier.xyz
In reply to: Tom Lane (#2)
Re: use_remote_explain missing in docs of postgres_fdw

On Fri, Feb 22, 2013 at 5:13 PM, Tom Lane <tgl@sss.pgh.pa.us> wrote:

Michael Paquier <michael.paquier@gmail.com> writes:

While testing a bit this feature, I noticed that use_remote_explain is
available in the list of options for FOREIGN TABLE and SERVER but this is
not specified in the docs:
http://www.postgresql.org/docs/devel/static/postgres-fdw.html

Wups ... for some reason it's "use_remote_estimate" in the docs. Thinko
on my part probably --- although on reflection, maybe that's a better
name anyway?

Indeed, use_remote_estimate is better. use_remote_explain makes it sound
like an EXPLAIN query would be sent to remote server. That is at least the
first impression I had when testing the feature without reading the docs.
--
Michael

#4Tom Lane
tgl@sss.pgh.pa.us
In reply to: Michael Paquier (#3)
Re: use_remote_explain missing in docs of postgres_fdw

Michael Paquier <michael.paquier@gmail.com> writes:

On Fri, Feb 22, 2013 at 5:13 PM, Tom Lane <tgl@sss.pgh.pa.us> wrote:

Wups ... for some reason it's "use_remote_estimate" in the docs. Thinko
on my part probably --- although on reflection, maybe that's a better
name anyway?

Indeed, use_remote_estimate is better. use_remote_explain makes it sound
like an EXPLAIN query would be sent to remote server. That is at least the
first impression I had when testing the feature without reading the docs.

Well, it does do that, at least for the part of the query that will be
executed on the remote server. But if you read it to mean the whole
query would be EXPLAINed on the remote server, that's wrong.

The objection I have to "use_remote_explain" is that it's focusing too
much on the mechanism (ie, send an EXPLAIN command for execution) rather
than the result (ie, get a cost estimate from the remote server).
So I'm inclined to change the code to match the docs rather than vice
versa. Anyone have a contrary opinion?

regards, tom lane

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