Cloudera Impala connect to Tableau Error

Question

I am working on using Tableau to connect to Cloudera Hadoop. I provide the server and port details and connect using Impala. I am able to successfully connect, select default Schema and choose the required table(s).

After this, when I drag and drop either a dimension or a measure to Rows/Columns on the grid, I get the below error:

[Cloudera][Hardy] (22) Error from ThriftHiveClient:

Query returned non-zero code: 10025, cause: FAILED:

SemanticException [Error 10025]: Line 1:7 Expression not in GROUP BY key ''.

I saw several similar problems on the forum, but none of them got the solution Any help on this is very much appreciated? 

Answer 1

• The error occurs when Tableau try to run something like this:

SELECT `table`.`param_1` AS `param_1` ,SUM(`table`.`param_2`) AS `sum_all` FROM `db_name`.`table` `table` GROUP BY 1

• Since you can check the schema and tables. This aggregation may cause the problem.

• You might need to check a few things:

  • Whether your odbc driver version correct or no as Tableau with Impala is not supported by Cloudera ODBC driver 2.5.28.

  • Whether you choose the right port number or login type or no. Impala port number is 21000 and 21050. Hive is 10000.

• In my case, the setup is using port 21050 and choose Impala as Type with no authentication. You can also choose Type as HiveServer2 and using impala port number to login. But it didn't work on my case.