Re: accessing multiple databases using dblink - Mailing list pgsql-general

From Marko Kreen
Subject Re: accessing multiple databases using dblink
Date
Msg-id e51f66da0712130531v1b02341bk70d6396802d71309@mail.gmail.com
Whole thread Raw
In response to accessing multiple databases using dblink  ("f.zamboni@mastertraining" <f.zamboni@mastertraining.it>)
List pgsql-general
On 12/13/07, f.zamboni@mastertraining <f.zamboni@mastertraining.it> wrote:
> Good morning to everybody,
> I've to resolve this situation: I've a collection of many different databases, all identical, and the name of those
databasesis stored inside a table in another "central 
> management" database.
> In an ideal world, I'd like with a single query to be able to recover the name of each database from the table that
doescontains them, and use it to do a query on each table on 
> each databse joining the results.
> At the moment I'm doing it by external code, but performaces are awfull...
> At first I tough something similar to
> select * from tab_databases,dblink('dbname=' || tab_databases.name,'select count(id) from tab_data')
> could work, but it seems its not allowed to reference rows from another table inside the from level.
>
> Putting dblink outside that level allow me to use the dynamic dbname, but in that case I would need a row resource,
whiledblink give back a table resource... 
>
> Is it possible to resolve this inside the databse?
> Thanks a lot...

This seems to be appropriate task for pl/proxy:

https://developer.skype.com/SkypeGarage/DbProjects/PlProxy

--
marko

pgsql-general by date:

Previous
From: Alvaro Herrera
Date:
Subject: Re: Slow PITR restore
Next
From: Bill Moran
Date:
Subject: Re: Need LIMIT and ORDER BY for UPDATE