JSON will be a core type in PostgreSQL 9.2
This is nice, but it's a shame that after going to the trouble of writing a JSON parser in C and incorporating it into the main Postgres codebase, they didn't go one step further and add a json_project_key function that pulls values out of a JSON blob.  That, combined with functional indices, allows you to store JSON blobs in your database <i>and</i> index on values inside them, or put another way, get the data model benefits of a NoSQL database [1] without sacrificing the mature Postgres internals.<p>The Heroku Postgres guys have been playing with this idea [2] using the PL/V8 plugin, which embeds Javascript as a supported language inside Postgres (and thus makes it trivial to implement the json_project_key function), but if Postgres is going to natively support JSON parsing then it shouldn't take an addon module to achieve this.<p>[1] Attempting to forestall the thread-jacking: I know NoSQL databases have other benefits besides their data model, but for some applications that's certainly <i>one of</i> the benefits.
[2] <a href="https://gist.github.com/1150804" rel="nofollow">https://gist.github.com/1150804</a>