Consider the following scenario:

You try to create an external table in PolyBase in SQL Server 2019 that has the following conditions:

  • One or more column definitions use database_default as the collation.

  • The external data source that's used is a HADOOP data source type.

In this situation, you receive an error message that resembles the following:

The given key was not present in the dictionary.


Microsoft has confirmed that this is a problem in the Microsoft products that are listed in the "Applies to" section.


This issue is fixed in the following cumulative update for SQL Server:

About cumulative updates for SQL Server:

Each new cumulative update for SQL Server contains all the hotfixes and all the security fixes that were included with the previous cumulative update. Check out the latest cumulative updates for SQL Server:


Learn about the terminology that Microsoft uses to describe software updates.

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