Postgres 11

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create table test(data jsonb);
insert into test(data) values(
'{"info":
[
	{
		"database": "Oracle",
		"company" : "Oracle"
	},
	{
		"database":"Sql Server",
		"company" :"Microsoft"
	},
	{
		"database":"DB2",
		"company" :"IBM"
	}
]
}'
)
1 rows affected

select jsonb_set(data, '{info,License}','"Proprietary"'::jsonb,true) from test
ERROR:  path element at position 2 is not an integer: "License"