Re: mysql_fdw trouble

On 10/29/2015 11:20 AM, Dane Foster wrote:
> On Thu, Oct 29, 2015 at 2:04 PM, Tom Lane <tgl@sss.pgh.pa.us
> <mailto:tgl@sss.pgh.pa.us>> wrote:
>
>     Dane Foster <studdugie@gmail.com <mailto: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.

Before you give up I would file an issue here:

https://github.com/EnterpriseDB/mysql_fdw/issues

including the MySQL version also.

This issue:

https://github.com/EnterpriseDB/mysql_fdw/issues/42

indicates this type of thing has come up before and was fixed.

>
>
> Dane
> ​
>


--
Adrian Klaver
adrian.klaver@aklaver.com