Re: [PATCH] Negative Transition Aggregate Functions (WIP)

<p dir="ltr">Tom,<p dir="ltr">I did not follow the thread very close, so I need to look what the ambiguity is there,
howeverI would love to see window rescans in explain analyze.<br /><p dir="ltr">I have great experience in tuning
Oraclequeries.<br /> There are features in PostgreSQL's explain analyze that I miss badly in Oracle: 'rows removed by
filter'is my favourite one. Improving explain analyze is great for performance analysis.<p dir="ltr">I would say target
audiencefor 'explain analyze' is not all the users, but someone closer to 'performance engineers'. Those beings are
usedto triple-check results and build/validate hypothesis since all the counters tend to lie, so 'a bit misleading
counter'is not a showstopper.<p dir="ltr">I did not think of
'non-being-able-to-use-negative-transition-since-floats-do-not-commute'before.<br /> Thanks to this discussion I see
whatkind of dragons live here.<p dir="ltr">I would vote (if I had any vote at all) for the inclusion of performance
statisticsto explain analyze (e.g. number of rescans and number of rows fed to aggregate) provided performance impact
istolerable in both regular and explain analyze mode.<p dir="ltr">I wonder how Oracle handles negative transition (does
it?),however that is a different discussion.<p dir="ltr">Regards,<br /> Vladimir Sitnikov