Re: auto-vacuum & Negative "anl" Values

Tom Lane wrote:
> The reason I didn't patch it myself is that I'm not quite clear on what
> *should* be happening here.  What effect should a large delete have on
> the ANALYZE threshold, exactly?  You could argue that a deletion
> potentially changes the statistics (by omission), and therefore inserts,
> updates, and deletes should equally count +1 towards the analyze
> threshold.  I don't think we are implementing that though.  If we want
> to do it that way, I suspect last_anl_tuples as currently defined is not
> the right comparison point.

Just as a point of reference, the old contrib pg_autovacuum counts ins +
upd + del against the analyze threshold where as the vacuum threshold
only compares against  upd + del.