What are drawbacks of setting REPLICA IDENTITY FULL in PostgreSQL table I want to use the wal2json extension to capture the changes in the PostgreSQL database. 
I need to find the diff between old and new rows. 
Having searched the Internet for an answer, I realized that this can be achieved by setting the REPLICA IDENTITY FULL option on the table of interest.

I think this is exactly what I need, but I wonder are there any significant drawbacks of this setting?
The only disadvantage is that it will produce more data than are necessary to identify the affected row, but since that is what you want, it is not a disadvantage to you.