Good question :-) You can do as ddorian43 explained, by including a payload in your notification (using JSON or another format). Or you can do as you suggeste

Good question :-) You can do as ddorian43 explained, by including a payload in your notification (using JSON or another format). Or you can do as you suggested and query the database to fetch more information about the change. Apart LISTEN/NOTIFY, which is a very powerful feature, PostgreSQL also provides "logical decoding" which solves problems similar to the ones solved by oplog tailing.