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JCouture
Frequent Visitor

Very Slow Power Query

Hey everyone,

I am having some issues with a Query refresh that we have to do on a weekly basis. It basically goes into a Sharepoint folder, opens and merges all of the files in there, and then does a bunch of transformations so we can use the data to report our performance metrics.

The refresh takes ~15mins and only gets longer after each week. Any help that could make this faster would be appreciated!

 

let
Source = Sharepoint_Weekly,
#"Invoke Custom Function1" = Table.AddColumn(Source, "Transform File (2)", each #"Transform File (2)"([Content])),

#"Renamed Columns1" = Table.RenameColumns(#"Invoke Custom Function1", {"Name", "Source.Name"}),
#"Removed Other Columns1" = Table.SelectColumns(#"Renamed Columns1", {"Transform File (2)"}),
#"Expanded Transform File (2)1" = Table.ExpandTableColumn(#"Removed Other Columns1", "Transform File (2)", {"ORDEN", "CODSUC", "CODMAQ", "NUMSER", "CODUSU"}, {"Datetime", "Product", "Press", "Serial #", "User ID"}),
#"Filtered Rows1" = Table.SelectRows(#"Expanded Transform File (2)1", each ([Product] <> null)),
#"Changed Type" = Table.TransformColumnTypes(#"Filtered Rows1", {{"Datetime", type datetime}, {"Product", type text}, {"Press", type text}, {"Serial #", Int64.Type}, {"User ID", Int64.Type}}),
#"Merged Queries" = Table.NestedJoin(Table.Buffer(#"Changed Type"), {"Serial #"}, Table.Buffer(CAPScrapWeekly), {"Serial #"}, "CAPScrapWeekly", JoinKind.LeftOuter),
#"Expanded CAPScrapWeekly" = Table.ExpandTableColumn(#"Merged Queries", "CAPScrapWeekly", {"CQ", "Prod Date"}, {"CQ", "CAPScrapWeekly.Prod Date"}),
#"Added Custom6" = Table.AddColumn(#"Expanded CAPScrapWeekly", "Prod Date", each if DateTime.Time([Datetime]) < Time.From("07:00") then DateTime.Date(Date.AddDays([Datetime],-1)) else DateTime.Date([Datetime]), type date),
#"Added Custom" = Table.AddColumn(#"Added Custom6", "WeekNum", each Text.PadStart(Text.From(Date.WeekOfYear([Prod Date])),2,"0"), type text),
#"Replaced Value" = Table.ReplaceValue(#"Added Custom",null,"-",Replacer.ReplaceValue,{"CQ"}),
#"Replaced Value1" = Table.ReplaceValue(#"Replaced Value",each [Prod Date],each if [CQ]<>"-" then [CAPScrapWeekly.Prod Date] else [Prod Date],Replacer.ReplaceValue,{"Prod Date"}),

#"Changed Type4" = Table.TransformColumnTypes(#"Replaced Value1",{{"Prod Date", type date}}),
#"Removed Columns1" = Table.RemoveColumns(#"Changed Type4",{"CAPScrapWeekly.Prod Date"}),
#"Added Custom3" = Table.AddColumn(#"Removed Columns1", "Month", each Date.MonthName([Prod Date])),

#"Added Custom7" = Table.AddColumn(#"Added Custom3", "Date-Shift", each if DateTime.Time([Datetime])>=Time.From("7:00") and DateTime.Time([Datetime])<Time.From("19:00") then Date.ToText([Prod Date],"yyyy-MM-dd") & "-" & "D" else Date.ToText([Prod Date],"yyyy-MM-dd") & "-" & "N")
in
#"Added Custom7"

4 REPLIES 4
JCouture
Frequent Visitor

I only added those buffers this morning and haven't seen any noticeable change, to be honest. I'll give the video a watch and give an update if it changes anything

Anonymous
Not applicable

Yeah I would remove those buffers. 

--Nate

ppm1
Solution Sage
Solution Sage

How many files are you combining? It is probably the merge step that is causing the slowness. A couple suggestions:

 

1. See if you can leverage incremental refresh as described in this video - https://www.youtube.com/watch?v=IVMdg16yBKE

 

2. Is your query faster if you remove the Table.Buffer's?

 

Pat

 

Microsoft Employee
JCouture
Frequent Visitor

No significant changes with/without the buffers

And I should have specified that I am actually using Excel for this, whereas that video shows an example for Power Bi.

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