This is likely not a bug, so please point me in the right direction if that is the case.
The -general list is you best choice if you know its not a bug but don't know where else to send the email.
In our application, a copy of the local database is made at launch using... CREATE DATABASE myCopy FROM TEMPLATE currentDB;
On linux and MacOS this operation completed in 5 seconds or so. On Windows (10 at present) it takes over a minute or more.
I would like to understand why this would be, and what might be done to speed it up on Windows.
Less capable hardware on the Windows box? Use better hardware? This isn't my area of expertise but I'm doubtful that any significant fault/difference exists within the PostgreSQL software. Is the data involved identical?
