Re: WIP: preloading of ispell dictionary

Pavel Stehule wrote:
> 2010/3/24 Craig Ringer <craig@postnewspapers.com.au>:
> > Pavel Stehule wrote:
> >
> >> Personally I dislike idea some dictionary precompiler - it is next
> >> application for maintaining and maybe not necessary.
> >
> > That's the sort of thing that can be done when first required by any
> > backend and the results saved in a file for other backends to mmap().
> > It'd probably want to be opened r/w access-exclusive initially, then
> > re-opened read-only access-shared when ready for use.
> >
> > My only concern would be that the cache would want to be forcibly
> > cleared at postmaster start, so that "restart the postmaster" fixes any
> > messsed-up-cache issues that might arise (not that they should) without
> > people having to go rm'ing in the datadir. Even if Pg never has any bugs
> > that result in bad cache files, the file system / bad memory / cosmic
> > rays / etc can still mangle a cache file.
> >
> > BTW, mmap() isn't an issue on Windows:
> > ?http://msdn.microsoft.com/en-us/library/aa366556%28VS.85%29.aspx
> > It's spelled CreateFileMapping, but otherwise is fairly similar, and is
> > perfect for this sort of use.
> >
> > A shared read-only mapping of processed-and-cached tsearch2 dictionaries
> > would save a HUGE amount of memory if many backends were using tsearch2
> > at the same time. I'd make a big difference here.
> >
> 
> If you know this area well, please, enhance my first patch. I am not
> able to oppose to Tom, who has a clean opinion on this patch :(

Should we add a TODO?

-- 
  Bruce Momjian  <bruce@momjian.us>        http://momjian.us
  EnterpriseDB                             http://enterprisedb.com

  PG East:  http://www.enterprisedb.com/community/nav-pg-east-2010.do