try {
  # do a lot of hard work
  # store the data in the db
  # clean up intermediate files
  # move the CSV file to an "archive" dir
}
catch {
  # clean up intermediate files, potentially clean up any db records etc
}

try {   
  # start a transaction
    # do a lot of hard work   
    # store the data in the db   
    # clean up intermediate files   
    # move the CSV file to an "archive" dir 
  # commit the transaction
} 
catch {   
  # rollback everything: files, db changes, the whole thing
}

#
# Source: DotJim blog (http://dandraka.com)
# Jim Andrakakis, July 2019
#
# Prerequisite: 
#   1) internet connectivity
#   2) nuget command line must be installed 
#      (see https://www.nuget.org/downloads).
# If nuget is not in %path%, you need to change 
#   the installation (see below) to call it with 
#   its full path.
 
# Stop on error
$ErrorActionPreference = "Stop"

if ($psISE)
{
    $binPath = Split-Path -Path $PSISE.CurrentFile.FullPath        
}
else
{
    $binPath = $PSScriptRoot
}
$alphaFSver = "2.2.6"
$libPath = "$binPath\AlphaFS.$alphaFSver\lib\net40\AlphaFS.dll"
$basePath = "$binPath\..\alphatest"

# ====== installation ======
if (-not [System.IO.File]::Exists($libPath)) {
    Out-File -FilePath "$binPath\packages.config" `
        -Force `
        -Encoding utf8 `
        -InputObject ("<?xml version=`"1.0`" encoding=`"utf-8`"?><packages>" + `
          "<package id=`"AlphaFS`" version=`"$alphaFSver`" targetFramework=`"net46`" />" + `
          "</packages>")
    cd $binPath
    & nuget.exe restore -PackagesDirectory "$binPath"
}
# ==========================
 
# Make sure the path matches the version from step 2
Import-Module -Name $libPath
 
if (-not (Test-Path $basePath)) {
    New-Item -ItemType Directory -Path $basePath
}
 
# Check if the filesystem we're writing to supports transactions.
# On a FAT32 drive you're out of luck.
$driveRoot = [System.IO.Path]::GetPathRoot($basePath)
$driveInfo = [Alphaleonis.Win32.Filesystem.DriveInfo]($driveRoot)
if (-not $driveInfo.VolumeInfo.SupportsTransactions) {
    Write-Error ("Your $driveRoot volume $($driveInfo.DosDeviceName) " + `
      "[$($driveInfo.VolumeLabel)] does not support transactions, exiting")
}
 
# That's some example data to play with.
# In reality you'll probably get data from a DB, a REST service etc.
$list = @{1="Jim"; 2="Stef"; 3="Elena"; 4="Eva"}
 
try {
    # Transaction starts here
    $transactionScope = [System.Transactions.TransactionScope]::new([System.Transactions.TransactionScopeOption]::RequiresNew)
    $fileTransaction = [Alphaleonis.Win32.Filesystem.KernelTransaction]::new([System.Transactions.Transaction]::Current)
 
    # Here we're doing random stuff with our files and dirs, 
    #   just to show how this works.
    # The important thing to remember is that for the transaction 
    #   to work correctly, ALL methods you use have to be -transacted.
    # I.e. you must not use AppendText() but AppendTextTransacted(), 
    #   not CreateDirectory() but CreateDirectoryTransacted() etc etc.
    $logfileStream = [Alphaleonis.Win32.Filesystem.File]::AppendTextTransacted($fileTransaction, "$basePath\list.txt")
    foreach($key in $list.Keys) {
        $value = $list.$key
        $filename = "$([guid]::NewGuid()).txt"
        $dir = "$basePath\$key"
 
        Write-Host "Processing item $key $value"
 
        if (-not [Alphaleonis.Win32.Filesystem.Directory]::ExistsTransacted($fileTransaction, $dir)) {
            [Alphaleonis.Win32.Filesystem.Directory]::CreateDirectoryTransacted($fileTransaction, $dir)
        }
        [Alphaleonis.Win32.Filesystem.File]::WriteAllTextTransacted($fileTransaction, "$basePath\$key\$filename", $value)        
        $logfileStream.WriteLine("$filename;$key;$value")
    }
    $logfileStream.Close()
     
    # to simulate an error and subsequent rollback:
    # Write-Error "Something not great, not terrible happened"
     
    # Commit transaction
    $transactionScope.Complete()
    Write-Host "Transaction committed, all modifications written to disk"
}
catch {
    Write-Host "An error occured and the transaction was rolled back: '$($_.Exception.Message)'"
    throw $_.Exception
}
finally {
    if ($null -ne $logfileStream -and $logfileStream -is [System.IDisposable]) {
        $logfileStream.Dispose()
        $logfileStream = $null
    }    
    if ($null -ne $transactionScope -and $transactionScope -is [System.IDisposable]) {
        $transactionScope.Dispose()
        $transactionScope = $null
    }    
}