Re: Minimal logical decoding on standbys

I noticed the tests added in this patch set are very slow.  Here are 
some of the timings:

...
[13:26:59] t/018_wal_optimize.pl ................ ok    13976 ms
[13:27:13] t/019_replslot_limit.pl .............. ok    10976 ms
[13:27:24] t/020_archive_status.pl .............. ok     6190 ms
[13:27:30] t/021_row_visibility.pl .............. ok     3227 ms
[13:27:33] t/022_crash_temp_files.pl ............ ok     2296 ms
[13:27:36] t/023_pitr_prepared_xact.pl .......... ok     3601 ms
[13:27:39] t/024_archive_recovery.pl ............ ok     3937 ms
[13:27:43] t/025_stuck_on_old_timeline.pl ....... ok     4348 ms
[13:27:47] t/026_standby_logical_decoding.pl .... ok   117730 ms  <<<

Is it possible to improve this?