Simon Riggs wrote: > Returning to Matteo's original query, what we are saying is that the new > optimization for MIN/MAX queries doesn't work with inherited tables. > > It could do, by running optimize_minmax_aggregates() for each query that > gets planned to see if a better plan exists for each child table. > > I think that's a TODO item.
Great. Of course I'm using ORDER BY ... LIMIT as a workaround to get the index scan on pre-8.1, and because I'm used to it insted of the previously not optimized MIN/MAX aggregates.
> Optimizing ORDER BY and LIMIT down looks like it would be harder to do > in the general case, even if Matteo's simple transform looks good. I'm > not sure it's a very common query type though...
If I can find some time, I'll try to write some hacks... I just need to find out where to start ;)
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