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Comment by yangyang | Hacker News Reader

The improvements to hstore (primarily to make it hierarchical and add array support) ended up becoming jsonb.

That is really exciting! I am going to take a serious look at jsonb and using Postgres now, although FoundationDB has caught my eye with its table group functionality: https://foundationdb.com/layers/sql/documentation/Concepts/t...

Table groups look rather like hierarchical databases [1], which were the norm before relational databases came along.

Do bear in mind that you'll never get MongoDB-style in-place updates in PostgreSQL, due to MVCC. You may save a round-trip with the entire JSON object once they implement update operators, though.

[1] http://en.wikipedia.org/wiki/Hierarchical_database_model

Could you confirm that you can atomically update a single item inside a jsonb field without reading/writing all of the jsonb data? I know this is possible with hstore (but not 9.3's json type), but can not find a clear answer for jsonb in the documentation. Any pertinent links would be much appreciated!

You can't. Others in this conversation have pointed out this is targeted for 9.5, though it may available as an extension before that.

I'm pretty sure you can using a stored procedure written with plv8. Though that's not exactly a fluent and elegant natural solution

You're only avoiding putting the whole thing on the wire twice.

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