PowerShell 7.3 - Difficulty with Handling Large CSV Files and Memory Management
I tried several approaches but none seem to work. I'm currently working with PowerShell 7.3 to process large CSV files that can exceed 1GB in size. My goal is to filter specific rows based on certain criteria and then export the results back into another CSV file. However, I'm running into memory issues when attempting to load the entire CSV at once, which results in an out-of-memory behavior. I've tried using `Import-Csv`, but the command fails with the following behavior message: ``` OutOfMemoryException: Exception of type 'System.OutOfMemoryException' was thrown. ``` To mitigate the scenario, I attempted to read the CSV in smaller chunks using `Get-Content`, and then pipe the lines to `ConvertFrom-Csv`, but I encountered a question with data integrity when filtering. The following code is what I've attempted: ```powershell $rows = Get-Content -Path 'C:\path\to\largefile.csv' -ReadCount 1000 | ConvertFrom-Csv $filteredRows = $rows | Where-Object { $_.Status -eq 'Active' } $filteredRows | Export-Csv -Path 'C:\path\to\filteredfile.csv' -NoTypeInformation ``` This approach consumes less memory, but I have noticed that it doesn't properly filter all rows as expected, leading to incomplete results. I've also considered using `StreamReader` for more efficient file handling, but I'm unsure how to properly convert those lines from the stream into objects for filtering. Can anyone suggest a more effective way to handle large CSV files in PowerShell while ensuring data integrity during processing? Are there specific best practices or design patterns for this kind of task? The stack includes Powershell and several other technologies. Hoping someone can shed some light on this.