Sample JSON for discourse debug: https://discuss.redash.io/t/working-with-json-datasource/5458

sample.json

{
  "data": [
    {
      "cost": "$51.00",
      "vendor_account_identifier": "9999-9999-9999",
      "vendor_account_name": "acct1"
    },
    {
      "cost": "$50.00",
      "vendor_account_identifier": "9999-9999-9998",
      "vendor_account_name": "acct2"
    },
    {
      "cost": "$52.00",
      "vendor_account_identifier": "9999-9999-9997",
      "vendor_account_name": "acct3"
    }
  ]
}