Forum Discussion
Refresh taking too long when using AddIndexColumn and Expand Lists
Try wrapping the statement immediately before adding the index with Table.Buffer() and see if that helps.
Hi edhans,
Thank you for your answer.
I never used Table.Buffer() before.
I tried using it, but it is even slower. I should have informed you that I have 1GB of data in my mailbox, and the person i'm working with has 7 distincts mailbox that can contain 33GB (max) each. Unfortunately I don't think the memory can handle that, even if some columns are deleted before using the Table.Buffer().
The only fast way of creating an index i've found here is to concatenate several fields.
With AddIndexColumns before the expand, when doing an Apply, it treats 400 rows almost instantly, and then they are treated 10 by 10.
Is there a temporary storing of data on the hard drive involved ?
Yes. Power Query caches data, but that speeds up development. It doesn't impact the report as the cache isn't used during the actual refresh.