> If `order by` is > not pushed down to the underlying database, then how does Calcite handle > this operator?
It will generate a plan with sort operator on top of the data source. > Will it read all data provided by the underlying database > and enumerate it to sort? I believe so. > If so, how to guarantee the performance while a > large amount of data? It is not guaranteed. So better to push down sort into data source, if not, you need to teach the Calcite-based optimizer to push it down. On 2020/11/03 03:05:10, Xiangwei Wei <[email protected]> wrote: > Hi all, > > I'd like to ask some questions about the Calcite adapter. If `order by` is > not pushed down to the underlying database, then how does Calcite handle > this operator? Will it read all data provided by the underlying database > and enumerate it to sort? If so, how to guarantee the performance while a > large amount of data ? > > Sorry to trouble you guys. But look forward to hearing from you :D > > -- > Best, > Xiangwei Wei >
