> On Wed, Dec 7, 2011 at 10:14 AM, Alex Bible <Alex.Bible@xxxxxxx> wrote: > > > > 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! > > dblink is a very thin wrapper for libpq. From the querying database, > the overhead is pretty light -- basically the query is fired and the > results are interpreted from text into whatever the database has in > the receiving result via the various typein functions. For all > intents and purposes, this is pretty similar to sending in queries > over the regular sql interface. One gotcha of course is that libpq > buffers the entire result in memory which can be dangerous, so be > advised. > > To the receiving database, dblink queries are no different from any > other query, except that they are not parameterized. Lack of > parameterization and access to the binary protocol are the major > downsides when using dblink. IMNSHO, dblink needs a variable argument > call that uses the paramterized interface. Also support for binary > transfer of data would be nice. > > merlin I find dblink being a nice tool as long as the data volume to transfer remains low. I've evaluated it to implement a clustered Postgres environment, but gave it up due to the poor performances. Still waiting for the binary transfer before the next try ;-) reagrds, Marc Mamin -- Sent via pgsql-general mailing list (pgsql-general@xxxxxxxxxxxxxx) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-general
