Usually, a good approach of optimizing SQL statement using DBLINK is that you could try your best to reduce data returned – calling remote table that is an in-line view. furthermore it also reduces the data via network transmission.
At the same time, it even hasn’t consumed the resource (more network waiting-events) from data transmission, this waiting-event is named to “SQL*Net message from DBLINK” on Oracle.
This subject will tell you the approach of optimization, and make the SQL statement run to completion from 5 minutes originally to only 7 seconds after optimizing, running efficiency improves 40 times than before.
