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Anonymous's avatar
Anonymous
Not applicable
6 years ago
Solved

List.Contains() is slow

Hi,   I am using = Table.SelectRows(Table1, each List.Contains(List, [UID])) to filter out 300 categories from a table that has 1.6mil rows. However, it is loading very slow when I apply the query ...
Need Help
  • v-kelly-msft's avatar
    v-kelly-msft
    6 years ago

    Hi Anonymous ，

     

    Are you using a direct query mode?Why not filter the table in table view?

     

    Best Regards,
    Kelly
     
    Did I answer your question? Mark my post as a solution!

     

ImkeF's avatar
ImkeF
Community Champion
6 years ago

Hi Anonymous  

this could be caused by the list not being buffered.

So whatever step you're referencing with "List", make sure to wrap it into a List.Buffer-function.

 

kemiogrst's avatar
kemiogrst
New Member
1 year ago

I would like to know how many items a buffered list can perform well before starting to get slow when called inside a "List.Contains" function. I tried with about 5k items and it seems good, but not with 350K items.
I usually use buffered lists to filter values in tables with codes like this:
If List.Contains(list, [field]) then true else false

Thanks in advance.