Horton

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

Tom Lane <tgl@sss.pgh.pa.us>

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From: Tom Lane <tgl@sss.pgh.pa.us>
To: Andreas Karlsson <andreas@proxel.se>
Cc: pgsql-hackers@postgreSQL.org, Andres Freund <andres@anarazel.de>
Date: 2017-04-13T16:13:30Z
Lists: pgsql-hackers 
Andreas Karlsson <andreas@proxel.se> writes:
> Here is my proof of concept patch. It does basically the same thing as 
> Andres's patch except that it handles quoted values a bit better and 
> does not try to support anything other than the regproc type.

> The patch speeds up initdb without fsync from 0.80 seconds to 0.55 
> seconds, which is a nice speedup, while adding a negligible amount of 
> extra work on compilation.

I've pushed this with some mostly-cosmetic adjustments:

* created a single subroutine that understands how to split DATA lines,
rather than having several copies of the regex

* rearranged the code so that the data structure returned by
Catalog::Catalogs() isn't scribbled on (which was already
happening before your patch, but it seemed pretty ugly to me)

* stripped out the bootstrap-time name lookup code from all of reg*
not just regproc.

There's certainly lots more that could be done in the genbki code,
but I think all we can justify at this stage of the development
cycle is to get the low-hanging fruit for testing speedups.

			regards, tom lane

Commits

  1. Attempt to identify system timezone by reading /etc/localtime symlink.

  2. Make sure to run one initdb TAP test with no TZ set

  3. Use one transaction while reading postgres.bki, not one per line.

  4. Move bootstrap-time lookup of regproc OIDs into genbki.pl.