Magnus Hagander's PostgreSQL blog

PostgreSQL 9.1 beta1 now available - now is a great time to start testing it, and trying out all the great new features.

There have always been a number of ways to read your PostgreSQL logs remotely, over a libpq connection. For example, you can use the pg_read_file() function - which is what pgadmin does. PostgreSQL 9.1 adds a new and more convenient way (in some ways) to do this - using SQL/MED.

PostgreSQL 9.1 comes with SQL standard SQL/MED functionality. The MED in is short for "Managemend of External Data", and as the name sounds, it's about accessing data that's external to the PostgreSQL server. The SQL/MED functionality is not (yet) complete, but it's already very useful in it's current state.

In SQL/MED, there is something called a Foreign Data Wrapper, that can be compared to a driver. Using this FDW, we can create one or more Foreign Servers, which is a definition of how to connect to a specific instance of the service - if any. Finally, we can create one or more Foreign Tables on each of the Foreign Servers, giving us direct access to the remote data using SQL.