Re: Re: BUG #13685: Archiving while idle every archive_timeout with wal_level hot_standby - Mailing list pgsql-hackers

From Andres Freund
Subject Re: Re: BUG #13685: Archiving while idle every archive_timeout with wal_level hot_standby
Date
Msg-id 20151103154300.GY11897@awork2.anarazel.de
Whole thread Raw
In response to Re: Re: BUG #13685: Archiving while idle every archive_timeout with wal_level hot_standby  (Robert Haas <robertmhaas@gmail.com>)
Responses Re: Re: BUG #13685: Archiving while idle every archive_timeout with wal_level hot_standby  (Michael Paquier <michael.paquier@gmail.com>)
Re: Re: BUG #13685: Archiving while idle every archive_timeout with wal_level hot_standby  (Michael Paquier <michael.paquier@gmail.com>)
List pgsql-hackers
On 2015-11-03 10:23:35 -0500, Robert Haas wrote:
> On Mon, Nov 2, 2015 at 12:58 AM, Jeff Janes <jeff.janes@gmail.com> wrote:
> > If a transaction holding locks aborts on an otherwise idle server, perhaps it will take a very long time for a
log-shippingstandby to realize this.  But I have hard time believing that anyone who cares about that would be using
log-shipping(rather than streaming) anyway.
 
> 
> I'm sure other people here understand this better than me, but I
> wonder if it wouldn't make more sense to somehow log this data only if
> something material has changed in the data being logged.

Phew. That doesn't seem easy to measure. I'm doubtful that it's worth
comparing the snapshot and such, especially in the back
branches.

We could maybe add something that we only log a snapshot if XXX
megabytes have been logged or something. But I don't know which number
to pick here - and if there's other write activity the price of a
snapshot record really isn't high.

Andres



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