Re: [HACKERS] Default setting for autovacuum_freeze_max_age

2016-10-26 Thread Thomas Munro
On Thu, Oct 27, 2016 at 6:55 AM, Josh Berkus wrote: > On 10/21/2016 10:29 AM, Robert Haas wrote: >> On Fri, Oct 21, 2016 at 1:17 PM, Josh Berkus wrote: >>> Particularly, with 9.6's freeze map, point (2) is even stronger reason >>> to *lower*

Re: [HACKERS] Default setting for autovacuum_freeze_max_age

2016-10-26 Thread Josh Berkus
On 10/21/2016 10:29 AM, Robert Haas wrote: > On Fri, Oct 21, 2016 at 1:17 PM, Josh Berkus wrote: >> Particularly, with 9.6's freeze map, point (2) is even stronger reason >> to *lower* autovacuum_max_freeze_age. Since there's little duplicate >> work in a freeze scan, a lot of

Re: [HACKERS] Default setting for autovacuum_freeze_max_age

2016-10-21 Thread Robert Haas
On Fri, Oct 21, 2016 at 1:17 PM, Josh Berkus wrote: > Particularly, with 9.6's freeze map, point (2) is even stronger reason > to *lower* autovacuum_max_freeze_age. Since there's little duplicate > work in a freeze scan, a lot of users will find that frequent freezing >

Re: [HACKERS] Default setting for autovacuum_freeze_max_age

2016-10-21 Thread Josh Berkus
On 10/21/2016 07:44 AM, Tom Lane wrote: > Bruce Momjian writes: >> Why is autovacuum_freeze_max_age's default set to 200 million, rather >> than something like 2 billion? It seems 2 billion is half way to >> wrap-around and would be a better default. Right now, the default

Re: [HACKERS] Default setting for autovacuum_freeze_max_age

2016-10-21 Thread Alvaro Herrera
Bruce Momjian wrote: > On Fri, Oct 21, 2016 at 10:44:41AM -0400, Tom Lane wrote: > > Bruce Momjian writes: > > > Why is autovacuum_freeze_max_age's default set to 200 million, rather > > > than something like 2 billion? It seems 2 billion is half way to > > > wrap-around and

Re: [HACKERS] Default setting for autovacuum_freeze_max_age

2016-10-21 Thread Bruce Momjian
On Fri, Oct 21, 2016 at 10:44:41AM -0400, Tom Lane wrote: > Bruce Momjian writes: > > Why is autovacuum_freeze_max_age's default set to 200 million, rather > > than something like 2 billion? It seems 2 billion is half way to > > wrap-around and would be a better default. Right

Re: [HACKERS] Default setting for autovacuum_freeze_max_age

2016-10-21 Thread Tom Lane
Bruce Momjian writes: > Why is autovacuum_freeze_max_age's default set to 200 million, rather > than something like 2 billion? It seems 2 billion is half way to > wrap-around and would be a better default. Right now, the default seems > to freeze 10x more often than it has to.

[HACKERS] Default setting for autovacuum_freeze_max_age

2016-10-21 Thread Bruce Momjian
Why is autovacuum_freeze_max_age's default set to 200 million, rather than something like 2 billion? It seems 2 billion is half way to wrap-around and would be a better default. Right now, the default seems to freeze 10x more often than it has to. Does it default to 200 million so clog can be