[SQL] Question on MERGE in postgresql - Mailing list pgsql-sql

Below is the SQL statement I used. Even after I removed the business logic part for debugging purpose, it dose not work. 

MERGE INTO util.comment C 

  USING util.comment_orig B 

  ON C.jl_id_per_book = B.jl_id_per_book

  WHEN MATCHED DO NOTHING;

 

ERROR:  syntax error at or near "MERGE"

LINE 2: MERGE INTO util.comment C 

        ^

********** Error **********

ERROR: syntax error at or near "MERGE"

SQL state: 42601

Character: 8

Any help is appreciated!

Thanks and Regards

Kalees.