bertwagner

-- This version of that data has new lines removed to save space.
-- Please see https://gist.github.com/bertwagner/965acde93706a9a5d772509e56247a1c for the neatly formatted version of the data.

DECLARE @WebsiteJson nvarchar(max) = '{ "Users": [ { "_id": "589f14e8427b0030d59615b1", "index": 0, "guid": "4a5ecd66-8c41-4553-9c1b-7597124b46e3", "isActive": true, "balance": "$1,418.71", "picture": "http://placehold.it/32x32", "age": 26, "eyeColor": "brown", "name": "Hanson Larson", "gender": "male", "company": "KENEGY", "email": "hansonlarson@kenegy.com", "phone": "+1 (804) 447-3852", "address": "698 Durland Place, Hachita, Louisiana, 1920", "about": "Consectetur laboris sunt proident ullamco ex excepteur duis cillum sit dolor occaecat officia. Sunt amet cupidatat enim mollit esse non minim dolore ullamco minim duis do. Sunt sint aliqua sit excepteur anim proident consequat magna reprehenderit laborum. Voluptate officia et duis sit laborum.\r\n", "registered": "2016-11-09T10:59:38 +05:00", "latitude": -72.754583, 

bertwagner

SELECT 
	NAME, 
	StringValue, 
	ValueType
FROM 
(
	SELECT 
		[NAME], 
		StringValue, 
		ValueType, 

bertwagner

SELECT 
	JSON_VALUE(value, '$.name') 
FROM 
	OPENJSON(@WebsiteJson,'$.Users')

bertwagner

-- Car data source: https://github.com/arthurkao/vehicle-make-model-data
IF OBJECT_ID('dbo.Cars') IS NOT NULL 
BEGIN
	DROP TABLE dbo.Cars;
END
CREATE TABLE dbo.Cars
(
	Id INT IDENTITY(1,1),
	CarDetails NVARCHAR(MAX)
);

bertwagner

-- Car data source: https://github.com/arthurkao/vehicle-make-model-data
IF OBJECT_ID('dbo.Cars') IS NOT NULL 
BEGIN
	DROP TABLE dbo.Cars;
END
CREATE TABLE dbo.Cars
(
	Id INT IDENTITY(1,1),
	CarDetails NVARCHAR(MAX)
);

bertwagner

-- Remember to turn on "Include Actual Execution Plan" for all of these examples

-- Before we add any computed columns/indexes, let's see our execution plan for our SQL statement with a JSON predicate
SELECT * FROM dbo.Cars WHERE JSON_VALUE(CarDetails, '$.model') = 'Golf'
/*
Output:
Id          CarDetails
----------- --------------------------------------------------
1113        {"year":2001,"make":"VOLKSWAGEN","model":"GOLF"}
2410        {"year":2002,"make":"VOLKSWAGEN","model":"GOLF"}

bertwagner

-- Add an index onto our computed column
CREATE CLUSTERED INDEX CL_CarModel ON dbo.Cars (CarModel)

-- Check the execution plans again
SELECT DISTINCT * FROM dbo.Cars WHERE JSON_VALUE(CarDetails, '$.model') = 'Golf'
SELECT DISTINCT * FROM dbo.Cars WHERE CarModel = 'Golf'
-- We now get index seeks!

bertwagner

-- Let's compare how quick Phil Factor's JSON parsing function does against the new SQL 2016 functions
-- Phil's parseJSON function can be downloaded from https://www.simple-talk.com/sql/t-sql-programming/consuming-json-strings-in-sql-server/

SELECT years.StringValue AS Year, makes.StringValue AS Make, models.StringValue AS Model FROM dbo.parseJSON(@cars) models
INNER JOIN dbo.parseJSON(@cars) years ON models.parent_ID = years.parent_ID
INNER JOIN dbo.parseJSON(@cars) makes ON models.parent_ID = makes.parent_ID
WHERE models.NAME = 'model' AND models.StringValue = 'Golf' AND years.NAME = 'year' AND makes.NAME = 'make'

bertwagner

-- Indexed computed column returns results in ~1ms
SELECT * FROM dbo.Cars WHERE CarModel = 'Golf'

bertwagner

-- Turn on stats and see how long it takes to parse the ~20k JSON array elements
SET STATISTICS TIME ON

-- Test #1
-- Test how long it takes to parse each property from all ~20k elements from the JSON array
-- SQL returns this query in ~546ms
SELECT JSON_VALUE(value, '$.year') AS [Year], JSON_VALUE(value, '$.make') AS Make, JSON_VALUE(value, '$.model') AS Model FROM OPENJSON(@cars, '$') 

-- Test #2
-- Time to deserialize and query just Golfs without computed column + index