Fistly- > bring your Table 1 in Tableau and pivot your Sub1.. Sub5 to get this
I have renamed the pivot columns to Subject and Grade.
2. After this bring in your second table and join it on subject to get this
3. Create a hierarchy of group and subject (from the second table)
and then arrange them as follows
Hope this helps
Thanks for your response. I can't pivot the columns because I have more than 80 millions of records. In a given example, I have considered 5 columns (Sub 1.. Sub 5) but in actual, I have 100 columns likewise. If I go with pivoting the columns, performance is getting worst.
Do you have any other suggestion?
As per as I know, you need to maintain a database for huge file. Pivot is good for limited number of columns and rows. You check alternative ways of data extraction into tableau.