Re: dblink performance

Le 2011-12-07 11:14, Alex Bible a écrit :
>
> Hello All,
>
> I'm currently on a development team utilizing PostgreSQL and we are
> looking into the possibility of using dblink to reference an external
> database (read only). Our system administrator and DBA were concerned
> about the performance impact that cross-database queries would have on
> a production application. Are there any known performance issues or
> anything of the like that I would need to know before pushing this
> issue further? I have been using PostgreSQL for the past couple months
> but this is my first time using dblink. I really just need an opinion
> from someone who has used this technology before. Thanks!
>
> Alexander E. Bible
>
>
Hello,

one problem is when you join local data with remote data. The optimizer
falls short on this when finding good plans and executing. If you
frequently need to join with non-volatile remote data, it's generally
better to make a snapshot of remote tables. It all depends on volume and
usage patterns of databases.

Interesting link:
http://www.postgresonline.com/journal/archives/44-Using-DbLink-to-access-other-PostgreSQL-Databases-and-Servers.html

hope that's help
Bruno Lavoie
bl(at)brunol(dot)com
bruno(dot)lavoie(at)gmail(dot)com