Tableau Data Blend Performance Level of Detail

Question

I have two blended sources where the source A has 500,000 rows and source B has 20,000. The problem is that when I use source A as the primary source, any computation in the dashboard takes far too long to be useful. When I use B as my primary source, performance is much improved.

The level of detail I need is in source A. When source B is primary I am left with the dreadful asterisk where there is a one-to-many relationship. For example, this is what I get:

Source A primary:

Event(from source B)  Occurred_On(from source A)
    ABC                      1/1/2000
    ABC                      5/10/2000
    XYZ                      9/9/2002
    XYZ                      4/5/2002

Source B primary:

Event(from source B)  Occurred_On(from source A)
    ABC                            *
    XYZ                            *

Data must be blended-- source A is an Oracle database and source B is a text file so a join is out of the question.

Is there any workaround?

Answer 1

If you are able to upgrade to version 10, you would be able to take advantage of joining two different data sources. If not, you can try importing the data from the text file into your Oracle database. Or you can follow these steps:

--> Cross database joins [a link] (http://www.tableau.com/about/blog/2016/7/integrate-your-data-cross-database-joins-56724)

--> Create a lookup table of the text file and apply a join a link

--> To improve the performance, create a data extract file of the combined dataset which will be the primary data source for the report [a link] (http://onlinehelp.tableau.com/current/pro/desktop/en-us/help.htm#extracting_data.html)

Also just 500K record should not cause the performance drag but it will be a good idea to recheck the server configuration and see if there are any bottlenecks present there.