IMPALA-11677

[hong7j]

Hi everyone！
    I created a new issue:
             https://issues.apache.org/jira/browse/IMPALA-11677
   In 
src/compat-apache-hive-3/java/org/apache/impala/compat/MetastoreShim.java. 
fireInsertEvents function can be very slow for tables with large number of 
partitions. Therefore I want to refactor it to an asynchronous call. Just like 
in impala-3.x.
  This is my first time creating impala issue. Can you assign this task to 
me？My  Jira username is Qihong Jiang.