Update polybase-troubleshooting.md

added transactional

Author: Ckarst

docs/relational-databases/polybase/polybase-troubleshooting.md

@@ -223,6 +223,8 @@ manager: "jhubbard"
  - When exporting data into an ORC File Format from SQL Server or Azure SQL Data Warehouse text heavy columns can be limited to as few as 50 columns due to java out of memory errors. To work around this, export only a subset of the columns.
  - Cannot Read or Write data encrypted at rest in Hadoop. This includes HDFS Encrypted Zones or Transparent Encryption.
  - PolyBase cannot connect to a Hortonworks instance if KNOX is enabled. 
+ - If you are using Hive tables with transactional = true, PolyBase cannot access the data in the Hive table's directory. 
+
 
 [PolyBase doesn't install when you add a node to a SQL Server 2016 Failover Cluster](https://support.microsoft.com/en-us/help/3173087/fix-polybase-feature-doesn-t-install-when-you-add-a-node-to-a-sql-server-2016-failover-cluster)