Hi, I don't know which repository you have taken this driver from, but code from https://github.com/citusdata/mongo_fdw/blob/master/mongo_fdw.c gives connectStatus = mongo_connect(mongoConnection, addressName, portNumber); if (connectStatus != MONGO_OK) { errorCode = (int32) mongoConnection->err; mongo_destroy(mongoConnection); mongo_dispose(mongoConnection); ereport(ERROR, (errmsg("could not connect to %s:%d", addressName, portNumber), errhint("Mongo driver connection error: %d", errorCode))); } You have to find what errorcode = 3 means with your mongo installation/version. An other way, would be to add the full error message in this error report ... The best would probably to ask this question to people you wrote this extension ;o) Regards PAscal -- Sent from: http://www.postgresql-archive.org/PostgreSQL-admin-f2076596.html