Re: Gsoc2012 Idea --- Social Network database schema

> Subject: Re: [HACKERS] Gsoc2012 Idea --- Social Network database schema
> From: neil.conway@gmail.com
> To: huangqiyx@hotmail.com
> CC: daniel@heroku.com; josh@agliodbs.com; pgsql-hackers@postgresql.org
>
> 2012/3/19 Qi Huang <huangqiyx@hotmail.com>:
> >> I actually tried to find out, personally...not sure if I was searching
> >> wrongly, but searching for TABLESAMPLE did not yield a cornucopia of
> >> useful conversations at the right time in history (~2007), even when
> >> the search is given a broad date-horizon (all), so I, too, an
> >> uninformed as to the specific objections.
> >>
> >> http://www.postgresql.org/search/?m=1&q=TABLESAMPLE&l=&d=-1&s=d
> >
> > I sent a mail to Nail Conway asking him about this. Hope he could give a
> > good answer.
>
> I never tried to get TABLESAMPLE support into the main PostgreSQL tree
> -- I just developed the original code as an exercise for the purposes
> of the talk. Implementing TABLESAMPLE would probably be a reasonable
> GSoc project.
>
> My memory of the details is fuzzy, but one thing to check is whether
> the approach taken by my patch (randomly choose heap pages and then
> return all the live tuples in a chosen page) actually meets the
> standard's requirements -- obviously it is not true that each heap
> page has the same number of live tuples, so you aren't getting a truly
> random sample.
>
> Neil
>

Best Regards and Thanks