Re: Vacuum: allow usage of more than 1GB of work mem

On Fri, Apr 6, 2018 at 5:25 PM, Claudio Freire <klaussfreire(at)gmail(dot)com> wrote:
> On Fri, Apr 6, 2018 at 10:39 AM, Heikki Linnakangas <hlinnaka(at)iki(dot)fi> wrote:
>> On 06/04/18 01:59, Claudio Freire wrote:
>>>
>>> The iteration interface, however, seems quite specific for the use
>>> case of vacuumlazy, so it's not really a good abstraction.
>>
>>
>> Can you elaborate? It does return the items one block at a time. Is that
>> what you mean by being specific for vacuumlazy? I guess that's a bit
>> special, but if you imagine some other users for this abstraction, it's
>> probably not that unusual. For example, if we started using it in bitmap
>> heap scans, a bitmap heap scan would also want to get the TIDs one block
>> number at a time.
>
> But you're also tying the caller to the format of the buffer holding
> those TIDs, for instance. Why would you, when you can have an
> interface that just iterates TIDs and let the caller store them
> if/however they want?
>
> I do believe a pure iterator interface is a better interface.

Between the b-tree or not discussion and the refactoring to separate
the code, I don't think we'll get this in the next 24hs.

So I guess we'll have ample time to poner on both issues during the
next commit fest.