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New JSON features – The old lovely database is new again with 21c

Posted by FatDBA on August 21, 2021

Oracle Database supports relational, graph, spatial, text, OLAP, XML, and JSON data – yes, all at once in one database.
The Oracle Database 21c provides a native JSON data type in binary format. This data type can be used in tables, uses less space and is faster. It’s uniquely designed Oracle Binary JSON format (OSON) is able to speed up both OLAP and OLTP workloads over JSON documents.

I’d recently did some tests and found JSON datatype is now fully integrated into all components of the 21c database and have few new things added to improve its performance. This post is all about JSON datatype in the Oracle 21c Database eco-system, new features, improvements etc.

So, before I move ahead, would like to first build the foundation for the readers, lets create a table with with JSON Data and do some examples.

-- Create a table with JSON datatype.
CREATE TABLE testOrder
 (did NUMBER PRIMARY KEY, jdoc JSON)


-- Let's insert some data to the table
INSERT INTO testOrder
VALUES (1, ' {"testOrder": {
"podate": "2015-06-03",
"shippingAddress": {"street": "3467 35th Ave",
 "city" : "Clara", “state”: “CA”, "zip":
94612},
"comments" : "Discounted sales Foundation Day",
"sparse_id" :"PFHA35",
"items": [
 {"name" : "TV", "price": 341.55, "quantity": 2,
 "parts": [
 {"partName": "remoteCon", "partQuantity": 1},
 {"partName": "antenna”, "partQuantity": 2}]},
 {"name": “PC”, “price”: 441.78, "quantity": 10,
 "parts": [
 {"partName": "mousepad", "partQuantity": 2},
 {"partName": "keyboard", "partQuantity": 1}]}
]}}');



-- Do some SELECT ops
SELECT did,
 po.jdoc.testOrder.podate.date(),
 po.jdoc.testOrder.shippingAddress,
 po.jdoc.testOrder.items[*].count(),
 po.jdoc.testOrder.item[1]
FROM testOrder po
WHERE po.jdoc.testOrder.podate.date() =
TO_DATE(‘2015-06-03’,'YYYY-MM-DD') AND
po.jdoc.testOrder.shippingAddress.zip.number()
BETWEEN 84610 AND 84620;


SELECT JSON {
 ‘name’ : li.itemName,
 ‘sales’ : li.price * li.quantity
}
FROM lineItems_rel li 




-- That's how to UPDATE 
UPDATE testOrder po
SET jdoc = JSON_TRANSFORM(jdoc,
 REPLACE
‘$.testOrder.shippingAddress.city’
 = ‘Oakland’,
 REPLACE ‘$.testOrder.shippingAddress.zip’
 = 94607,
 SET '$.testOrder.contactPhone' =
 JSON('["(415)-867-8560","(500)312-8198"]'),
 REMOVE ‘$.testOrder.sparse_id’,
 APPEND ‘$.testOrder.items’ =
 JSON(‘{“items” :[{“name”:”iphone”,
 “price” : 635.54, “quantity” :2}]}’))
WHERE po.jdoc,testOrder.podate.date() =
 TO_DATE(‘2019-07-01’); 

So, that’s how you can create, query, update your JSON data in any table, pretty cool right 🙂

Okay, coming back to the purpose of the post – What is new in Oracle 21c in terms of JSON support ?

  • Though JSON data type was added in Oracle 20c to provide native support, but is generally available in version 21c.
  • Earlier to 21c, users can only use a single-value functional index to accelerate JSON_VALUE() predicate evaluation. Antecedently, a functional index was bounded to index at most one value per row for JSON that meant a field value having at most one occurrence. In 21c, a user can create a multi-value functional index on a JSON datatype column to index elements within a JSON array. This speeds up the rating of JSON_EXISTS() – an operator allowing the use array of equivalence predicates of the SQL/JSON path language.
  • Oracle 21c includes several other enhancements to the JSON functionality in the database JSON_SCALAR function, that creates an instance of a JSON type from a SQL scalar value.
  • JSON_TRANSFORM function was introduced in Oracle Database 21c to make JSON data alterations simpler or easier in complexity.

Hope It Helped!
Prashant Dixit

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