Thread: Foreign data wrappers and indexes on remote side

Foreign data wrappers and indexes on remote side

From
Filip Rembiałkowski
Date:
Hi.

Is there any way to take use of indexes on foreign tables?

Currently (at least with tds_fdw, that I was testing) the planner just
does a dumb full sequential scan in all cases.

That is

SELECT drink FROM foreignbar;

-- takes as much time as

SELECT drink FROM foreignbar where drink_key = 3210;


Thanks!


Re: Foreign data wrappers and indexes on remote side

From
Tom Lane
Date:
=?UTF-8?Q?Filip_Rembia=C5=82kowski?= <filip.rembialkowski@gmail.com> writes:
> Is there any way to take use of indexes on foreign tables?

> Currently (at least with tds_fdw, that I was testing) the planner just
> does a dumb full sequential scan in all cases.

That would be something to discuss with the author of tds_fdw.  It's
mostly on the head of each individual FDW how smart plans for it will be.

            regards, tom lane


Re: Foreign data wrappers and indexes on remote side

From
"David G. Johnston"
Date:
On Fri, Jun 26, 2015 at 12:09 PM, Filip Rembiałkowski <filip.rembialkowski@gmail.com> wrote:
Hi.

Is there any way to take use of indexes on foreign tables?

Currently (at least with tds_fdw, that I was testing) the planner just
does a dumb full sequential scan in all cases.

That is

SELECT drink FROM foreignbar;

-- takes as much time as

SELECT drink FROM foreignbar where drink_key = 3210;

​It is possible but implementation is the responsibility of the FDW middleware authors.

Since "tds_fdw" is not core this would not be the correct forum.

David J.
 

Re: Foreign data wrappers and indexes on remote side

From
Filip Rembiałkowski
Date:
Is WHERE clause push-down implemented in any known fdw?

Thank you.



On Fri, Jun 26, 2015 at 6:19 PM, Tom Lane <tgl@sss.pgh.pa.us> wrote:
> =?UTF-8?Q?Filip_Rembia=C5=82kowski?= <filip.rembialkowski@gmail.com> writes:
>> Is there any way to take use of indexes on foreign tables?
>
>> Currently (at least with tds_fdw, that I was testing) the planner just
>> does a dumb full sequential scan in all cases.
>
> That would be something to discuss with the author of tds_fdw.  It's
> mostly on the head of each individual FDW how smart plans for it will be.
>
>                         regards, tom lane


Re: Foreign data wrappers and indexes on remote side

From
"David G. Johnston"
Date:
On Fri, Jun 26, 2015 at 3:31 PM, Filip Rembiałkowski <filip.rembialkowski@gmail.com> wrote:
Is WHERE clause push-down implemented in any known fdw?


David J.