Mutations and Subscriptions¶

Mutations and subscriptions are not supported.

Group BY¶

The _groupBy clause is only supported for fields of the main entity of the query. For example:

Grouping by fields of related entities is not supported by the Denodo GraphQL Service.

{
    "errors": [
        {
            "message": "Error in _groupBy clause: Grouping by navigational fields is not supported.",
            "extensions": {
                "orderByField": "orders.total_price",
                "invalidClause": "_groupBy",
                "classification": "ValidationError"
            }
        }
    ],
    "data": {
        "order_detail": []
    }
}

Handling of Very Large Result Sets¶

Due to the output validation and serialization requirements imposed by the GraphQL specification, it’s recommended to use large page sizes if the result sets are potentially very large. This way you will reduce the number of pages needed to iterate the result and overall data retrieval performance will improve. However, note that the page size could affect the amount of server memory used by the Denodo GraphQL Service.

Support for Void Stored Procedures¶

Due to the GraphQL specification enforcement that all object types must define at least one non-introspection field (GraphQL empty object types are not supported), the GraphQL service does not support Virtual DataPort void stored procedures, i.e., stored procedures that do not have any return field. Therefore, any void stored procedures existing in a database will not be included in the database GraphQL schema. Consequently, queries on this kind of stored procedures are not allowed either.