The JDBC driver tries to handle this by estimating how much data has been buffered. It mainly comes up when executing batch INSERTS as a large number of statements may be sent to the backend prior to reading back any results.
There's a nice write up of the potential deadlock and the driver's logic to avoid it here: https://github.com/pgjdbc/pgjdbc/blob/7c0655b3683efa38cbe0d029385d8889f6392f98/org/postgresql/core/v3/QueryExecutorImpl.java#L300 Regards, -- Sehrope Sarkuni Founder & CEO | JackDB, Inc. | https://www.jackdb.com/
