Reading across databases

Postgresql 7.4.5 (pgaccess and psql) RedHat 8

Is there a way of 'cross accessing' databases?
We tend to use three environments for development - a dev_ , test_ and rel_ prefixed database then exists - one for each environment. There are occasions when it is very useful to be able to, say, load the test_ database with some data that has already been created in the dev_ database. I was hoping that a command such as:

INSERT INTO test_agents:someTable
    SELECT *
         FROM dev_agents:someTable

OR simply
SELECT blah FROM databaseName:tableName.....

Is such a feature available?

Regards, Steve Tucknott ReTSol Ltd DDI: 01903 828769