Referencing joined table loading every time

[myu2017]

Hi, 

I have loaded two CSV and created two tables, and joined them as a Joined table. 

Every time I reference the Joined table, I see that CSV files are getting loaded again. Since those CSV files are very large, it loads for several minutes. 

How to avoid this, if there is a way?

Thanks in advance. 

Regards,

Myu

[jennratten]

Hello - are you performing the join as a new query or within an existing query?  Joining as a new query should solve this problem.  When the join is done within an existing query (the join is not the first step in the query), a separate call to the source is made for each row.  I have included a link where this is explained in more detail.

https://docs.microsoft.com/en-us/power-query/optimize-expanding-table-columns#:~:text=When%20queries... 

[myu2017]

Thank you for your help. 

I am actually merging with new query. 

As you can see from the screenshot above, whatever transformation/calculation I do in the "Not available in Oil" query, I see that the query is loading the CSVs again.