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azuresql-server-2016azure-synapsepolybase

Azure PolyBase external table from StorageTable


Can somebody explain to me why I can polybase reference an azure BlobStorage as external table but not an azure StorageTable? Did I missed it some where in the documentary? Its some kind of ironic for me if I don't missed it and it is really not possible.

Related to @wBob answer

I created a uservoice idea, please vote if you found this is a feature that is missing:

https://feedback.azure.com/forums/307516-sql-data-warehouse/suggestions/19014286-support-of-storagetable-as-datasource


Solution

  • Azure Table Storage can store more No-SQL structures so is potentially more complicated than your average flat-file. Even different rows can have different schemas as per this example. Polybase on the other hand is optimised for highly-structured flat files and loading high volume at high speed. It has a fairly simple interface where you can set the file type, separators, a few failure options, but not much else. So in answer to your question, Table Storage data could potentially be more complicated than could be optimised for high speed loading via a simple interface like Polybase.

    However this is not a problem as Azure Data Factory can import from Table Storage:

    Azure Data Factory with Azure Table Storage

    Polybase has recently been extended to support Azure Data Lake Store (ADLS). If you feel strongly about this, you could post a feedback request:

    https://feedback.azure.com/forums/307516-sql-data-warehouse