Re: Vacuum/visibility is busted

On 7 February 2013 19:15, Jeff Janes <jeff.janes@gmail.com> wrote:
> On Thu, Feb 7, 2013 at 10:09 AM, Pavan Deolasee
> <pavan.deolasee@gmail.com> wrote:
>>
>> Right. I don't have the database handy at this moment, but earlier in
>> the day I ran some queries against it and found that most of the
>> duplicates which are not accessible via indexes have xmin very close
>> to 2100345903. In fact, many of them are from a consecutive range.
>
> Does anyone have suggestions on how to hack the system to make it
> fast-forward the current transaction id? It would certainly make
> testing this kind of thing faster if I could make transaction id
> increment by 100 each time a new one is generated.  Then wrap-around
> could be approached in minutes rather than hours.

This is a variation of one of the regression tests...

CREATE OR REPLACE FUNCTION burn_xids (n integer)
RETURNS void
LANGUAGE plpgsql
AS $$
BEGINIF n <= 0 THEN RETURN; END IF;PERFORM burn_xids(n - 1);RETURN;
EXCEPTION WHEN raise_exception THEN NULL; END;
$$;

-- Simon Riggs                   http://www.2ndQuadrant.com/PostgreSQL Development, 24x7 Support, Training & Services