Overview

Denodo is a powerful data virtualization platform that provides its users with a JSON format of query results that are accessed through its REST API. We seek to provide users with the Denodo JSON format in an effort to allow them to quickly integrate RDS output into existing applications designed to work against the Denodo JSON format. The only difference is that users can still include our metadata if desired using the metadata parameter.

Denodo Compliant Data

In this example we will assume we have a collection "test" and view "view" created with the variables "salary","category", and "weight".

A standard query would look like this:

Standard Select

http://{host}/rds/catalog/test/testStats/select

Standard Select Output

{
    "records": [
        [
            10000,
            1,
            0.2
        ],
        [
            20000,
            2,
            0.5
        ],
        [
            152666,
            2,
            0.75
        ]
    ],
    "info": {
        "colOffset": 0,
        "colCount": 3,
        "moreCols": false,
        "format": "MTNA",
        "includeMetadata": false,
        "limit": 20,
        "offset": 0,
        "moreRows": false
    }
}

By adding the format parameter we can get this output in Denodo's format.

Denodo Select

http://{host}/rds/catalog/test/testStats/select?format=denodo

Denodo Output

{
    "name": "",
    "elements": [
        {
            "salary": 10000,
            "category": 1,
            "weight": 0.2
        },
        {
            "salary": 20000,
            "category": 2,
            "weight": 0.5
        },
        {
            "salary": 152666,
            "category": 2,
            "weight": 0.75
        }
    ],
    "links": []
}

In addition to the Denodo format, users can also include the MTNA metadata section if desired.

Denodo Select With Metadata

http://{host}/rds/catalog/test/testStats/select?format=denodo&metadata

Denodo Output With Metadata

{
    "name": "",
    "metadata": {
        "variables": {
            "resources": [
                {
                    "id": "salary",
                    "name": "salary",
                    "index": 1,
                    "storageType": "NUMERIC",
                    "displayType": "NUMERIC",
                    "width": 12
                },
                {
                    "id": "category",
                    "name": "category",
                    "index": 2,
                    "storageType": "NUMERIC",
                    "displayType": "NUMERIC",
                    "width": 10
                },
                {
                    "id": "weight",
                    "name": "weight",
                    "index": 3,
                    "storageType": "NUMERIC",
                    "displayType": "NUMERIC",
                    "width": 12
                }
            ],
            "info": {
                "offset": 0,
                "more": false,
                "count": 3
            }
        }
    },
    "elements": [
        {
            "salary": 10000,
            "category": 1,
            "weight": 0.2
        },
        {
            "salary": 20000,
            "category": 2,
            "weight": 0.5
        },
        {
            "salary": 152666,
            "category": 2,
            "weight": 0.75
        }
    ],
    "links": []
}