Buffer pool statistics in Explain Analyze

<div dir="ltr">Hi,<br /><br />I believe it makes sense adding some more details to explain analyze output like the
numberof pages read/written.<br />This will allow one to understand the workload the query puts on the server making it
easierto tune queries, choose the best indices, etc.<br /><br />As far as I understand, this patch is rather trivial as
backend\storage\buffercollects the required information. The only thing is to add several fields to the struct
Instrumentation(include\executor\instrument.h), fill them in during Instr* calls in (backend\executor\instrument.c) and
updatebackend\commands\explain.c to report the collected data.<br /><div dir="ltr"><br />I think think this change is
goingto split page access statistics by each and every execution node (much like 'actual time' is split now).<br /><br
/>Willthis patch ever be accepted?<br /><br /><br />Regards,<br />Vladimir Sitnikov</div></div>