Re: postgres_fdw : disable extended queries

2016-10-24 10:36 GMT+02:00 Albe Laurenz <laurenz(dot)albe(at)wien(dot)gv(dot)at>:

> Nicolas Paris wrote:
> > I have a 9.6 pg instance, and I am trying to link a foreign postgresql
> database that do not accept
> > extended queries. (only simple queries https://www.postgresql.org/
> docs/current/static/protocol.html )
> >
> > When I run a query against the foreign pg instance thought postres_fdw,
> it looks like it sends a
> > transaction containing
> >
> > DECLARE c1 CURSOR FOR
> > SELECT customer_id FROM foodmart.customer
> >
> > -> is there a way to run a simple query with postgres_fdw such:
> >
> > SELECT customer_id FROM foodmart.customer
>
> No, it is part of the design that cursors are used, so that rows can be
> fetched one at a time and concurrent DML statements can be run.
>

​Actually problem is not with the cursor, sorry. Error message says it's
related to a prepared statement.
I am not able to debug it and see what is happening and what is the
prepared statement. ​

> You might consider using dblink.
>
​
Dblink works great, but It seems less flexible (no predicate push down). I
am able to create a view that encapsulate dblink, but all the rows are
fetch each time I use the view.

> Yours,
> Laurenz Albe
>