Reading txt-file, change rows to columns, save txt file - powershell

Question

I have a txt files (semicolon separated) containing over 3 million records where columns 1 to 4 have some general information. Columns 5 and 6 have detailed information. There can be up to 4 different detailed information for the same general information in columns 1 to 4.
My sample input:
Server;Owner;Company;Username;Property;Value
Srv1;Dave;Sandbox;kwus91;Memory;4GB
Srv1;Dave;Sandbox;kwus91;Processes;135
Srv1;Dave;Sandbox;kwus91;Storage;120GB
Srv1;Dave;Sandbox;kwus91;Variant;16
Srv2;Pete;GWZ;aiwq71;Memory;8GB
Srv2;Pete;GWZ;aiwq71;Processes;234
Srv3;Micael;P12;mxuq01;Memory;16GB
Srv3;Micael;P12;mxuq01;Processes;239
Srv3;Micael;P12;mxuq01;Storage;160GB
Srv4;Stefan;MTC;spq61ep;Storage;120GB
Desired output:
Server;Owner;Company;Username;Memory;Processes;Storage;Variant
Srv1;Dave;Sandbox;kwus91;4GB;135;120GB;16
Srv2;Pete;GWZ;aiwq71;8GB;234;;
Srv3;Micael;P12;mxuq01;16GB;239;160GB;
Srv4;Stefan;MTC;spq61ep;;;120GB;
If a values doesn't exist for general information (Columns 1-4) it has to stay blank.
My current code:
$a = Import-csv .\Input.txt -Delimiter ";"
$a | FT -AutoSize
$b = #()
foreach ($Server in $a.Server | Select -Unique) {
$Props = [ordered]#{ Server = $Server }
$Owner = ($a.where({ $_.Server -eq $Server})).Owner | Select -Unique
$Company = ($a.where({ $_.Server -eq $Server})).Company | Select -Unique
$Username = ($a.where({ $_.Server -eq $Server})).Username | Select -Unique
$Props += #{Owner = $Owner}
$Props += #{Company = $Company}
$Props += #{Username = $Username}
foreach ($Property in $a.Property | Select -Unique){
$Value = ($a.where({ $_.Server -eq $Server -and
$_.Property -eq $Property})).Value
$Props += #{ $Property = $Value }
}
$b += New-Object -TypeName PSObject -Property $Props
}
$b | FT -AutoSize
$b | Export-Csv .\Output.txt -NoTypeInformation -Delimiter ";"
After a lot of trying and getting errors: My script works.
But it takes a lot of time.
Is there a possibility to make performance better for around 3 Million lines in txt file? I'm calculating with more or less 2.5 Million unique values for $Server.
I'm running Windows 7 64bit with PowerShell 4.0.

Answer 1

try Something like this:
#Import Data and create empty columns
$List=import-csv "C:\temp\file.csv" -Delimiter ";"
#get all properties name with value not empty
$ListProperty=($List | where Value -ne '' | select property -Unique).Property
#group by server
$Groups=$List | group Server
#loop every rows and store data by group and Property Name
$List | %{
$Current=$_
#Take value not empty and group by Property Name
$Group=($Groups | where Name -eq $Current.Server).Group | where Value -ne '' | group Property
#Add all property and first value not empty
$ListProperty | %{
$PropertyName=$_
$PropertyValue=($Group | where Name -eq $PropertyName | select -first 1).Group.Value
$Current | Add-Member -Name $PropertyName -MemberType NoteProperty -Value $PropertyValue
}
$Current
} | select * -ExcludeProperty Property, Value -unique | export-csv "c:\temp\result.csv" -notype -Delimiter ";"