Query Output to CSV Permission Error PostgreSQL - postgresql

Question

I am writing a powershell script that outputs a query to a file. After connecting to the database, I get a permission denied error that i am not able to get around. This is a production database, so I cannot modify the existing table schema, just trying to write content to a file. I have also tried running the script below with the postgres (root) account, but had no luck.
Any help would be greatly appreciated.
$DBConnectionString = "Driver={PostgreSQL Unicode(x64)};Server=localhost;Port=5432;Database=PRPC;Uid=id;Pwd=pwd";
$DBCommandText = "copy (select * from table) to
'C:\Users\myUser\Desktop\output.txt' with csv;";
$DBConn = New-Object System.Data.Odbc.OdbcConnection;
$DBConn.ConnectionString = $DBConnectionString;
$DBConn.Open();
$DBCmd = $DBConn.CreateCommand();
$DBCmd.CommandText = $DBCommandText;
$DBCmd.ExecuteReader();
$DBConn.Close();

Answer 1

This depends a bit on the PostgreSQL version and how it was installed.
9.1 and older installed as the postgres operating system user on Windows by default. 9.2 and newer run as NETWORK SERVICE. In both cases you can change that default, e.g. to run under a domain account.
PostgreSQL's COPY command does file I/O as the user account the PostgreSQL server runs under. So that user must have write permission to the destination. Typically one user can't write to another user's home directory, so you're getting an error.
To permit this to work you'll need to create a directory then change its permissions in the Security properties tab so that the user PostgreSQL runs as has the right to write to it. You may also need to change the permissions on its containing directories so that PostgreSQL can read it; I'm not 100% sure of the details in the Windows permissions model, as I work mainly with unix systems.