Refreshing queries is so slow (15 to 20 min)

[09]

Hell all,

I'm using three csv folders as data sources for my database created in EXCEL with power query. When i refresh my main query, it takes so much time (from 15 to 20 minutes). I guess it is related to the merge function that i used to relate two tables. you'll find below the M code used to merge the two table. Any tips to improve the speed of this query? thank you by advance.

let
Source = Table.NestedJoin(#"HISTORIQUE MB52", {"CLE", "Date"}, #"UPS STOCK", {"material_Sloc", "Date"}, "UPS STOCK", JoinKind.LeftOuter),
#"UPS STOCK développé" = Table.ExpandTableColumn(Source, "UPS STOCK", {"Account", "FSL", "Ref 5 ", "Designator", "UPS QTY"}, {"Account", "FSL", "Ref 5 ", "Designator", "UPS QTY"}),
FilterRows = Table.SelectRows(#"UPS STOCK développé", each [UNR] <> 0 or [Blocked] <> 0 or [Returns] <> 0 or [UPS QTY] <> null)
in
FilterRows

[amitchandak]

@09 , Make sure both have date data type. Or try creating a number using date and use that to merge

[09]

Thank you @amitchandak. Is there a way to create a number for both columns  {"CLE", "Date"}?