Re: Extended Prefetching using Asynchronous IO - proposal and patch

On Thu, May 29, 2014 at 7:11 PM, John Lumby <johnlumby(at)hotmail(dot)com> wrote:
>> Nonetheless, getting the next tid out of the index may involve stepping
>> to the next index page, at which point you've lost your interlock
>
> I think we are ok as peeknexttuple (yes bad name, sorry, can change it
> ...
> never advances to another page :
>
> * btpeeknexttuple() -- peek at the next tuple different from any
> blocknum in pfch_list
> * without reading a new index page
> * and without causing any side-effects such as
> altering values in control blocks
> * if found, store blocknum in next element of pfch_list

Yeah, I was getting to that conclusion myself too.

We could call it amprefetchnextheap, since it does just prefetch, and
is good for nothing *but* prefetch.