Hi everyone,
I have three tables
first table has 300 million rows, second table has 30K rows and third table has around 100k rows.
Now my final dataset is a left join of first table with second table and third table retaining 300 million rows of data.
Two approaches :
- Make these joins in prep and connect with prep. Enable incremental refresh using load date time in prep.
- Do all the joins in tableau itself and create extract that is 300 million rows and put a full refresh every day. My first extract took one hour.
Which is better among these two approaches? I want to go with prep but I am unable to explain to my supervisor why prep is better in this case. I want to know the fundamentals. This is a simple join and prep can be easily replaced but data is heavy. I do not want the tableau dashboard to show no data at any point of the time.
Hi @Vaishnavi Kilambi
The bigger decision between using a full refresh or incremental is whether the historic records change. If the historic records change, then you have to use a full refresh. If the historic records don't change, then you can use an incremental, you also need a date field for the incremental refresh.
