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.
