drill-user mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From Boris Chmiel <boris.chm...@yahoo.com.INVALID>
Subject Re: Tableau / filter issues
Date Tue, 18 Aug 2015 12:04:00 GMT
Hi usersFor people facing the same problem, here the workaround in case Tableau Quick filters
does not populate. You need to enforce the column data type manually and not let Tableau do
it by itself. Here is 2 approaches to do it :
- create a "raw" view on top of a parquet file with typed fields (slow perf) :CREATE VIEW
view1 AS (SELECT * FROM parquet);Note that that you cannot rename columns or you will loose
the underlying data type
- Or, create a view with formatted fields (better perf) : CREATE VIEW view1 AS (SELECT CAST(field1
AS Varchar(x)) field1, ......FROM parquet);

     Le Lundi 17 août 2015 18h07, Boris Chmiel <boris.chmiel@yahoo.com.INVALID> a écrit

 Hi Matt,
We also hide as far as possible queries by creating tables and views within Drill. As a result
we only have one massive table within Tableau. This approach proved to be efficient with
this kind of BI tools. 
My specific issue is about dynamic filtering within Tableau on a dimension field (let says
Year). Dimensions fields work well in rows / columns / color / size etc, but not as a filter. 

    Le Lundi 17 août 2015 17h10, Matt <bsg075@gmail.com> a écrit :

 I think Tableau also uses the first query to fetch the structure / 
metadata of the expected result set.

We have often eliminated performance issues using Tableau by "hiding" 
the structure of queries by putting them in database views. Could that 
be a possible solution here?

On 17 Aug 2015, at 11:02, Boris Chmiel wrote:

> Hello Driller,
> I'm facing issues using the Filter function of Tableau with Drill : 
> Tableau always populates values of the filter with "null".The action 
> is translated into 2 queries within Drill :
> SELECT \* FROM (SELECT field FROM Table GROUP BY field ORDER BY field 
> SELECT field FROM Table GROUP BY field ORDER BY field ASC
> It seems that Tableau is fetching the result of the first query (null 
> - which seems to by generated to catch exceptions) instead of the 
> second one.
> Anyone already met this issue ? Is there a workaround or customization 
> parameter to ajust ?
> conf : Tableau v9.0 + MapRDrillODBC driver with TDC file 
> deployedDrill V1.1.0

  • Unnamed multipart/alternative (inline, None, 0 bytes)
View raw message