Re: pg_upgrade and statistics

Greg Stark <stark@mit.edu> writes:
> On Tue, Mar 13, 2012 at 1:38 AM, Daniel Farina <daniel@heroku.com> wrote:
>> You probably are going to ask: "why not just run ANALYZE and be done
>> with it?"

> Uhm yes. If analyze takes a long time then something is broken. It's
> only reading a sample which should be pretty much a fixed number of
> pages per table. It shouldn't take much longer on your large database
> than on your smaller databases.

The data collection work does scale according to the statistics target,
which is something that's crept up quite a lot since the code was
originally written.

I wonder whether it'd be worth recommending that people do an initial
ANALYZE with a low stats target, just to get some stats in place,
and then go back to analyze at whatever their normal setting is.

			regards, tom lane