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Schema on Read feature in Azure DW RRS feed

  • Question

  • Hi All,

    I am new to Azure so I wanted to achieve Schema on Read functionality. So does azure DW support reading without loading data into the table . If yes, how can I acheive that.?

    Thanks!


    Wednesday, March 15, 2017 6:13 AM

Answers

  • This isn't quite true.

    Schema on Read generally means determining data types and column names on data access, not before.

    PolyBase is Schema on Write because it requires you to create external tables with data types and schema before reading the data. PolyBase is also strongly typed using SQL semantics, meaning that if the data is not in the specified format, it will be rejected.

    That being said, you can explore data in Azure Blob Storage and Azure Data Lake store using PolyBase.

    Hope that helps.

    -Casey

    Thursday, March 16, 2017 4:41 PM

All replies

  • Hi Ayush,

    This is possible with Polybase. You can read data from Azure Blob Storage or Azure Data Lake Store. You can find a Polybase guide here: https://msdn.microsoft.com/en-us/library/mt143171.aspx


    Jorg Klein's Microsoft Business Intelligence Blog

    Wednesday, March 15, 2017 8:18 AM
  • This isn't quite true.

    Schema on Read generally means determining data types and column names on data access, not before.

    PolyBase is Schema on Write because it requires you to create external tables with data types and schema before reading the data. PolyBase is also strongly typed using SQL semantics, meaning that if the data is not in the specified format, it will be rejected.

    That being said, you can explore data in Azure Blob Storage and Azure Data Lake store using PolyBase.

    Hope that helps.

    -Casey

    Thursday, March 16, 2017 4:41 PM
  • Hi Casey,

    You are right about the schema on read part, I overlooked that part of the question. I focused on the “reading without loading” question, which is possible with Polybase.

    Thanks for the addition!

    Jorg


    Jorg Klein's Microsoft Business Intelligence Blog

    Friday, March 17, 2017 12:03 PM