Re: Database creation performance drop going from pg 14 to pg 15+

["Mahdi Bahrami" <pgsql@xxxxxxxxxxx>]

Here's what the OP of the PostgresNIO issue has mentioned about what performance impact usage of `file_copy` has in his setup (https://github.com/SwiftPackageIndex/SwiftPackageIndex-Server/pull/3812):

Series: Default Strategy
Suite AllTests passed after 5.081 seconds
Suite AllTests passed after 5.274 seconds
Suite AllTests passed after 5.306 seconds
Suite AllTests passed after 5.224 seconds
Suite AllTests passed after 6.343 seconds
Suite AllTests passed after 5.450 seconds
Series: file_copy Strategy
Suite AllTests passed after 4.729 seconds
Suite AllTests passed after 4.755 seconds
Suite AllTests passed after 4.739 seconds
Suite AllTests passed after 4.772 seconds
Suite AllTests passed after 4.866 seconds
Suite AllTests passed after 4.855 seconds

This is them running the tests in parallel multiple times with and without file_copy, just to benchmark.
Overall ~0.5-6s / ~10% speedup, which isn't too significant at this level, but is still a noticeable relative improvement.