Comment by tgarma1234

The fact that you can pass attributes for a record into the JSONB field without defining the table structure in advance is really the decisive feature because then you never have to bother with changing your data model. For example, if you have contacts streaming into your table from Android devices you don't need to say whether or not there should be a column for "work email" and "home email2" etc etc... you just send everything into a column with key/value pairs and you can put whatever key/value pairs you want in that column. And then query over the keys without inserting a gazillion nulls into your database for rows that don't have a value for a particular key. You can also do updates on the json column AND you get all of the benefits of relational databases with other columns in the same table. I can't really see how anyone would not love this data type now that I have been exposed to it in production.