Github user mebelousov commented on the issue:
https://github.com/apache/zeppelin/pull/2442
@zjffdu, you are right, sessionPrecode is renamed to statementPrecode.
Since 0.8.0 I will recommend to run JDBC interpreter per note in isolated
mode due to Interpreter Lifecycle Manager: the table results accumulate in
ResourcePool and JVMs grow in size, but ILM will drop non-active JVMs.---
