A calculated field based on a parameter will generally not be able to take advantage of indexing, or other performance advantages.
You may need to adjust your approach so you can take advantage of the extract or your database.
Alternate routes depend on your exact situation, sometimes a table calc, other times a data blend, or using the parameter to switch the sheet out on a dashboard.
Can you create a sample packaged workbook that represents your situation?
Thanks Joe. I work in the health care industry so due to privacy issues I can't post a packaged workbook. The problem is that I had to create a calculated date field to coincide with our fiscal year because for some reason even if you set a date field to the fiscal year start when you create a calculated field it reverts back to the calendar year. I also have a calculation that uses a denominator that depends on the number of days in a date period so this needs to dynamically change when a users views data Yearly, Quarterly or Monthly which is on my dashboard. The little cross hair or drillup buttons on the dashboard...can I dynamically filter others graphs based on on action when someone clicks on these data drilldown or rollups? I can seem to reference this date drilldown or rollup in any calculations. Anyway, this time dimension is making my dashboard slow as an old dog. If I can't do this dynamic date drilldown/rollup that applies to other graphs in my dashboard I might need to essentially create three distinct dashboards, one for Yearly, one for Quarterly and one for Monthly aggregated data but I'm not sure how to create a parameters that dpending on what you select switches views to the different dasbhoards? I don't want 3 tabs on my dashboard, I want it to look more professional.
It does not need to be real data, just sample made up data in the same structure that you have. I would need to see exactly what you are doing (in a packaged workbook, .twbx) in order to provide applicable assistance.
Hi Ed, I also work in the healthcare world, and was using a parameter in a calculated field, and I too am experiencing extremely slow response rates even from within tableau desktop while I am designing the dashboard. Mine is a simple percentage - it is setup to calculate a utilization rate based on the percentage targeted (which is the parameter). It's a very simple calculation, but tableau sits there forever after I drag the calculated field into the view. I was wondering if you had found a workaround for this? I think it's unusual - I have used parameters in calculations in the past, and never experienced this, so I have to wonder if it is linked to the latest release of tableau??
We are still using 7.05 with SQL Server 2012 and parameters with dates seem to run fast. We have hesitated to upgrade since things are working well at the moment. In the beginning we were using Oracle and extracts and it was painful especially when trying to search text. We have had an issue with which driver to use due to the length of the text data which in some cases may be as high as 29999 but we found that using the ODBC driver for sql server 11 allowed the entire text to be displayed. The reason that I bring this up is that although the ODBC driver allows the large text fields it has issues with dates and stops some calculated fields. We are trying to find a way around it at the moment. If you don't have large text fields I would definitely recommend sql server 2012 rather than Oracle extracts in Tableau.