Re: Visibility map and freezing

On Fri, 2009-01-09 at 13:49 +0200, Heikki Linnakangas wrote:
> Thinking about this some more, I'm not too happy with those names 
> either. vacuum_freeze_scan_age and autovacuum_freeze_scan_age don't mean 
> quite the same thing, like vacuum_cost_delay and 
> autovacuum_vacuum_cost_delay do, for example.

If the distinction you're making is that autovacuum_freeze_max_age
affects the launching of a vacuum rather than the behavior of a vacuum,
maybe we could incorporate the word "launch" like:

autovacuum_launch_freeze_threshold

> I'm now leaning towards:
> 
> autovacuum_freeze_max_age
> vacuum_freeze_table_age
> vacuum_freeze_min_age
> 
> where autovacuum_freeze_max_age and vacuum_freeze_min_age are unchanged, 
> and vacuum_freeze_table_age is the new setting that controls when VACUUM 
> or autovacuum should perform a full scan of the table to advance 
> relfrozenxid.

I'm still bothered by the fact that "max" and "min" really mean the same
thing here.

I don't think we can perfectly capture the meaning of these GUCs in the
name. I think our goal should be to avoid confusion between them.

Regards,Jeff Davis