On 2015-02-21 17:43:09 +0100, Andres Freund wrote:
> One thing I was considering was to do the regtype and regproc lookups
> directly in the tool. That'd have two advantages: 1) it'd make it
> possible to refer to typenames in pg_proc, 2) It'd be much faster. Right
> now most of initdb's time is doing syscache lookups during bootstrap,
> because it can't use indexes... A simple hash lookup during bki
> generation could lead to quite measurable savings during lookup.
I've *very* quickly hacked this up. Doing this for all regproc columns
gives a consistent speedup in an assert enabled from ~0m3.589s to
~0m2.544s. My guess is that the relative speedup in optimized mode would
actually be even bigger as now most of the time is spent in
AtEOXact_CatCache.
Given that pg_proc is unlikely to get any smaller and that the current
code is essentially O(lookups * #pg_proc), this alone seems to be worth
a good bit.
The same trick should also allow us to simply refer to type names in
pg_proc et al. If we had a way to denote a column being of type
relnamespace/relauthid we could replace
$row->{bki_values} =~ s/\bPGUID\b/$BOOTSTRAP_SUPERUSERID/g;
$row->{bki_values} =~ s/\bPGNSP\b/$PG_CATALOG_NAMESPACE/g;
as well.
The changes in pg_proc.h are just to demonstrate that using names
instead of oids works.
Greetings,
Andres Freund
--
Andres Freund http://www.2ndQuadrant.com/
PostgreSQL Development, 24x7 Support, Training & Services
