Re: syncing with a MySQL DB

On Sat, Oct 25, 2008 at 1:19 PM, Ernesto Quiñones <ernestoq(at)gmail(dot)com> wrote:
> I use dbi-link, work fine, but I have problems when I call mysql
> tables "linked" and these tables are big, maybe a millon records, the
> answers is really slow, I need to wait 5 or more minutes to have an
> answer in a single query like this "select * from table limit 10", I
> am thinking maybe dbi-link download all the data to pgsql before to
> give me the answer.

Yes, that's what Postgres is doing. DBI-link is currently incapable
of pushing down the predicate to the remote system because Postgres
can't give it access to the predicate.

> Anybody knows how improve this?

If I have to push the predicate down, I'll generally write a
set-returning function which takes some of the predicate, limit, and
offset info to build a dynamic sql query against the remote database
using dblink.

--
Jonah H. Harris, Senior DBA
myYearbook.com