Re: Cutting initdb's runtime (Perl question embedded)

Andreas Karlsson <andreas(at)proxel(dot)se> writes:
> Looked some at this and what take time now for me seems to mainly be
> these four things (out of a total runtime of 560 ms).

> 1. setup_conversion: 140 ms
> 2. select_default_timezone: 90 ms
> 3. bootstrap_template1: 80 ms
> 4. setup_schema: 65 ms

FWIW, you can bypass select_default_timezone by setting environment
variable TZ to a valid timezone name before calling initdb. On
my workstation, that currently cuts the time for "initdb --no-sync"
from about 1.25 sec to just about exactly 1.0 sec.

I doubt that we want all the buildfarm members to switch over to
doing that, since then we'd lose coverage of select_default_timezone.
But it's interesting to speculate about having the buildfarm script
extract the selected timezone name out of postgresql.conf after the
first initdb it does, and then set TZ for remaining tests. We surely
don't need to test select_default_timezone more than once per
buildfarm run.

regards, tom lane