On Tue, Apr 12, 2016 at 8:59 AM, Justin Clift <justin@postgresql.org> wrote:
> On 12 Apr 2016, at 13:37, Robert Haas <robertmhaas@gmail.com> wrote:
>> On Tue, Apr 12, 2016 at 3:21 AM, Magnus Hagander <magnus@hagander.net> wrote:
>>> I think that may turn out to be one of those "hidden gems" of this release.
>>> As in being the one that nobody talks about now, but then a few years down
>>> the road it's the one that everybody talks about. But it's somewhat hard to
>>> explain to people who (1) don't know how the system really works (though
>>> that would count for things like snapshot too old as well) or (2) actually
>>> have run into the current problem (why hey, that's also the same with
>>> snapshot too old)
>>
>> Agreed. Unfortunately, for many people, the first time they really
>> become aware of autovacuum is when all of their tables hit the freeze
>> threshold for the first time. And this doesn't help with that. You
>> still have to scan everything after 200 million transactions; it's
>> just that you no longer have to do it again every 200 million
>> transactions after that. I still think it's a great feature, though.
>
> Er... we don't provide a warning ahead of time in the logs or something?
No. That would be a little strange, honestly. I have to assume that
many wraparound vacuums go totally unnoticed; how would you
distinguish the ones that are likely to annoy somebody from the other
ones?
--
Robert Haas
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