Hi,
I have a requirement in Tableau, wherein I need to save historic data in form of snapshot. So when in future the data changes I have snapshot of my historic data. My concern is if I change the joins between tables that are used in this extract, will the extract work? Or do I need to update the extract again.
example: If I have two tables A and B, when I create the extract the joins I specify is A.id=B.id. But later I wish to change it to A.rowid=B.rowid. I need to maintain the historic data and not update the extract with new records.
Appreciate your help!
Hi, Manjiri
I don't think you can do this.
But if your you populate the same columns from the query, you probably can use union for two different periods.
e.g,
select * from A a
left join B b
on a.id = b.id
where date between xxxx and xxxx
union
select * from A a
left join B b
on a.Rowid = b.Rowid
where date between yyy and yyyy
Hope this could help
ZZ