Re: mysql_fdw trouble - Mailing list pgsql-general

From Dane Foster
Subject Re: mysql_fdw trouble
Date
Msg-id CA+Wxin+gKig3dPF4x9wsxrEbThWaiCOum0s+FMujtkiuRFGSZg@mail.gmail.com
Whole thread Raw
In response to Re: mysql_fdw trouble  (Tom Lane <tgl@sss.pgh.pa.us>)
Responses Re: mysql_fdw trouble  (Adrian Klaver <adrian.klaver@aklaver.com>)
Re: mysql_fdw trouble  (John R Pierce <pierce@hogranch.com>)
Re: mysql_fdw trouble  (Dane Foster <studdugie@gmail.com>)
List pgsql-general
On Thu, Oct 29, 2015 at 2:04 PM, Tom Lane <tgl@sss.pgh.pa.us> wrote:
Dane Foster <studdugie@gmail.com> writes:
> Installation and set up worked flawlessly but when I run the following query
> ...
> ​I get the following error:​
> ​ERROR:  failed to prepare the MySQL query:
> FUNCTION latest.btrim does not exist

It looks like mysql_fdw is messing up by sending the trim() checks for
remote execution when there is no suitable function on the remote side.
Don't know whether that's a bug in mysql_fdw, or whether there's some
setup you're supposed to perform on the mysql server and have omitted.

                        regards, tom lane
​I think you are correct about mysql_fdw "... sending the trim() checks for remote execution" because according to the docs:

"The latest version will push-down the foreign table where clause to the foreign server. The where condition on the foreign table will be executed on the foreign server hence there will be fewer rows to to bring across to PostgreSQL. This is a performance feature."

I guess using mysql_fdw is a no-go for my data migration needs.


Dane

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