First, if you have manually added the string key value PervasiveEngineOptions\TempFileDirectory to the Windows registry, PSQL uses the path set for TempFileDirectory. (The registry location differs depending on the bit architecture of the product. For PSQL 32-bit Server, the location is HKEY_LOCAL_MACHINE\SOFTWARE\ODBC\ODBC.INI. For PSQL 64-bit Server, the location is HKEY_LOCAL_MACHINE\SOFTWARE\Wow6432Node\ODBC\ODBC.INI.)
For output and display only, the session-level command SET DECIMALSEPARATORCOMMA can be used to specify output (for example, SELECT results) that uses the comma as the decimal separator. This command has no effect on data entry or storage.
The first select statement above, if executed from the client, returns: