[alexhill]

Basically yes. hstore and json have entirely separate interfaces in Postgres, but the storage properties of hstore are a subset of json as you say. json/jsonb is generally more powerful, and will supplant hstore in a lot of new projects.

However hstore has been a part of Postgres since version 8.2 released in 2006, and I think was around as a third-party project before that, so it's used by a lot of projects.

It's also easier to manipulate hstore values then json values within the database. hstore's simplicity allows operators for combining and subtracting hstore values[0] which json doesn't have. Due to its restrictions, an hstore can also be converted to and from a record type (think database row). JSON fields on the other hand will generally be populated by your app and then only queried by the database.

[0] http://www.postgresql.org/docs/9.4/static/hstore.html#HSTORE...

[shreyas056]

Thanks for the explanation. So this means that Django does not support JSON or JSONB field types yet

[alexhill]

Not built-in, but there are plenty of third-party JSON fields around.

However, the author of contrib.postgres opened this PR yesterday, so you can certainly expect them in the next release: https://github.com/django/django/pull/4427

[shreyas056]

Great! this is very helpful