How to set parquet data types in copy activity sink?

joba-2596 5 Reputation points
2023-01-30T07:59:44.62+00:00

I'm trying to copy csv to parquet files using copy activity. However, I'm not succeeding in writing typed data to parquet. Whatever I do, all the fields in the parquet end up as "BYTE_ARRAY" (string):

Parquet schema viewer

The mapping I'm currently using looks like this:

"mapping": {
    "type": "TabularTranslator",
    "mappings": [           
        {
            "source": {
                "name": "REQUEST_ID",
                "type": "String",
                "physicalType": "String"
            },
            "sink": {
                "name": "request_id",
                "type": "String",
                "physicalType": "UTF8"
            }
        },
        [...]
        {
            "source": {
                "name": "t_job_id",
                "type": "INT32",
                "physicalType": "String"
            },
            "sink": {
                "name": "t_job_id",
                "type": "Int32",
                "physicalType": "INT_32"
            }
        },
        [...]
    ]
}

What am I doing wrong? The jobid and fileid fields are "additional columns" added by the copy activity, but they are definetley valid integers

User's image

The warnings in the additional columns say: Expression of type 'Int' does not match the field: 'value' but I'm not sure what that means. I can cast them to Strings in the expression to make the warning go away, but that doesn't solve the parquet problem either.

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