Re: More detail on settings for pgavd?

Josh Berkus wrote:

> Shridhar,
> 
> I was looking at the -V/-v and -A/-a settings in pgavd, and really don't 
> understand how the calculation works.   According to the readme, if I set -v 
> to 1000 and -V to 2 (the defaults) for a table with 10,000 rows, pgavd would 
> only vacuum after 21,000 rows had been updated.   This seems wrong.
> 
> Can you clear this up a little?   I'd like to tweak these settings but can't 
> without being better aquainted with the calculation.
> 
> Also, you may want to reverse your default ratio for Vacuum/analyze frequency.  
> True, analyze is a less expensive operation than Vacuum, but it's also needed 
> less often -- only when the *distribution* of data changes.    I've seen 
> databases where the optimal vacuum/analyze frequency was every 10 min/once 
> per day.

Will look into it. Give me a day or so. I am planning couple of other patches as 
well. May be over week end.

Is this urgent?

  Shridhar