Setting Additional Configuration

The advanced driver configuration properties are described in the following section:

  • MAX_CHAR_SIZE: It specifies the maximum size of columns of SQL_CHAR that the driver describes through result set descriptions and catalog functions. Add the MAX_CHAR_SIZE property and add a value if you do not want to use the default value, which is 100000. However, some tools require the maximum value to be set below a particular limit.

    Example: For Microsoft SQL Server, you must set this value equal to or less than 8000.

  • SCHEMA_NAME: Add this property and enter the schema name as its value, to filter to that schema while fetching metadata so that only the related TABL_SCHEM configured is exposed.

  • CATALOG_NAME: Add this property and enter the catalog’s name as its value.

  • USE_S3: This property is enabled/set to true by default. It is set to bypass QDS Control Plane for getting results directly from the S3 location. You can enter false later to disable it or remove the keyword.

  • BUCKET_REGION: Add this property as a keyword and enter the AWS region which you use as the cloud object storage for final results (default storage location (defloc)). If you do not specify the AWS region, then it defaults to us-east-1 AWS region.

    Caution

    STREAM_RESULTS mentioned below is part of the ODBC Driver beta versions 2.0.0 and 2.1.0. The beta versions can cause data loss in scenarios where results data has NULL characters (0x00) and are therefore not recommended for production usage. For more information, see Launch Stage and Availability of Features.

  • STREAM_RESULTS: Set it to true to enable Presto FastStreaming. It enables streaming of results directly from AWS S3 in the ODBC driver. This is in contrast to the earlier behavior wherein the driver waits for the query to finish before downloading any results from the QDS Control Plane or from S3. The streaming behavior can help the BI tool performance as results are displayed as soon as they are available in S3. Presto FastStreaming for ODBC driver is supported in Presto versions 0.193 and 0.208. As streaming cannot be used with Presto Smart Query Retry, the Presto FastStreaming feature automatically disables Presto Smart Query Retry.

    Note

    Create a ticket with Qubole Support to enable the Presto FastStreaming feature on the account.

  • VIRTUAL_HOST_STYLE: It is enabled by default. Set it to false to enable path-style URLs that allow a dot in the (.) S3 bucket name of the default storage location (defloc). It is only supported from ODBC Driver version 2.2.1.

    Here is an example of the ODBC driver’s advanced configuration.

    Caution

    STREAM_RESULTS mentioned below is part of the ODBC Driver beta versions 2.0.0 and 2.1.0. The beta versions can cause data loss in scenarios where results data has NULL characters (0x00) and are therefore not recommended for production usage. For more information, see Launch Stage and Availability of Features.

    [ec2-user@aws-instance ~]$ cat /etc/odbc.ini
    [ODBC]
    # Specify any global ODBC configuration here such as ODBC tracing.
    
    [ODBC Data Sources]
    Qubole ODBC Driver DSN=QuboleODBC
    
    [Qubole ODBC Driver DSN]
    # This key is not necessary and is only to give a description of the data source.
    Description=Qubole ODBC Driver DSN
    # Driver: The location where the ODBC driver is installed to.
    Driver=/usr/local/qubole/libquboleodbc.so
    # APITOKEN: The API Token for the Qubole account as provided by Qubole.
    APITOKEN=<API Token>
    # CLUSTER_LABEL: The label of the cluster on which queries are to be run.
    CLUSTER_LABEL=presto
    # ENDPOINT: The Qubole endpoint for the account as provided by Qubole.
    ENDPOINT=https://api.qubole.com
    #DSI: The data source name: Hive, Spark, Presto, or SQLCommand (for Quantum). The cluster label is not mandatory for Quantum.
    DSI=Presto
    # Maximum SQL_CHAR
    MAX_SQL_CHAR=10000
    # Schema name
    SCHEMA_NAME=default
    # Catalog name
    CATALOG_NAME=hive
    #S3 Bucket region
    BUCKET_REGION=us-west-1
    #Bypass QDS Control Plane
    USE_S3=true
    #Enable Presto FastStreaming
    STREAM_RESULTS=true
    #Enable Path-style URLs
    VIRTUAL_HOST_STYLE=false