Re: Reviewing freeze map code

On 7/1/16 3:43 PM, Andres Freund wrote:
> On 2016-07-01 15:42:22 -0500, Jim Nasby wrote:
>> On 7/1/16 2:23 PM, Andres Freund wrote:
>>>>> The only
>>>>> cost of that is that vacuum will come along and mark the page
>>>>> all-visible again instead of skipping it, but that's probably not an
>>>>> enormous expense in most cases.
>>> I think the main cost is not having the page marked as all-visible for
>>> index-only purposes. If it's an insert mostly table, it can be a long
>>> while till vacuum comes around.
>>
>> ISTM that's something that should be addressed anyway (and separately), no?
>
> Huh? That's the current behaviour in heap_lock_tuple.

Oh, I was referring to autovac not being aggressive enough on 
insert-mostly tables. Certainly if there's a reasonable way to avoid 
invalidating the VM when locking a tuple that'd be good.
-- 
Jim Nasby, Data Architect, Blue Treble Consulting, Austin TX
Experts in Analytics, Data Architecture and PostgreSQL
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