Hi Maurin, if I understand our correctly, then Impala already works the way you want it to.
In your example, col1 and col2 will not be materialized and the coalesce() function will not be executed at all. Are you running into a specific issue with views that you want to fix? Maybe I'm misunderstanding. Alex On Thu, May 25, 2017 at 4:50 PM, Maurin Lenglart <[email protected]> wrote: > Hi, > I am working on some big data related technology. > And I am trying to get a sense on how hard will it be to enhance the views > in impala so whenever someone query a view, not all the columns of that > view are computed but only the necessary columns for that particular query. > > A simple exemple will be: > create view test_view_a as > select coalesce(col1,col2) as testCol1, col3 from physical_table1 > > Then if I do a query like this: > select col3 from test_view_a; > The coalesce for testCol1 should not occur because not being used. > > thanks >
