Sütun Tipleri - json

Giriş

Json verisi saklamak için kullanılır. Açıklaması şöyle.

The only difference between json & jsonb is their storage:

- json is stored in its plain text format, while
- jsonb is stored in some binary representation

There are 3 major consequences of this:

- jsonb usually takes more disk space to store than json (sometimes not)
- jsonb takes more time to build from its input representation than json
- json operations take significantly more time than jsonb (& parsing also needs to be done each time you do some operation at a json typed value)

When jsonb will be available with a stable release, there will be two major use cases, when you can easily select between them:

- If you only work with the JSON representation in your application, PostgreSQL is only used to store & retrieve this representation, you should use json.
- If you do a lot of operations on the JSON value in PostgreSQL, or use indexing on some JSON field, you should use jsonb.

Açıklaması şöyle. json tipi 2012 yılında PostgreSQL 9.2 ile eklendi. Yani jsonb sütün tipinden daha önce eklendi. 

In 2012, PostgreSQL 9.2 introduced the first JSON data type in Postgres. It had syntax validation but it stored the incoming document directly as text with white spaces included. It wasn't very useful for real-world querying, index-based searching, and other functionalities you would normally do with a JSON document.

Açıklaması şöyle.

...a JSON datatype (2012), and a potpourri of new features in PostgreSQL 10 (better native support for partitioning and replication, full text search support for JSON, etc.)

Örnek

Şöyle yaparız

CREATE TABLE IF NOT EXISTS posts (
   ...
   metadata json default '{}'
 );