Hi Faisal, That's an interesting idea - thanks for filing a JIRA for it. This isn't currently supported, nor would it be feasible with out existing equi-hash join mechanism which relies on 1) one side of the join being small enough to fit into memory, and 2) being able to do a map lookup from one side to the other through the join key specified in the ON clause. Even if it was supported, it'd likely be too expensive to actually execute, as the query engine doesn't have enough information to optimize it. It would be interesting to abstract this in some way in the definition of a built-in function.
I'd recommend an alternate approach for now: execute two separate queries both with an ORDER BY expression and then do a merge sort on the client as you iterate through the results of both queries. You can use any arbitrary built-in function in the ORDER BY. Thanks, James On Wed, Jun 18, 2014 at 7:11 PM, faisal moeen <[email protected]> wrote: > Hi there, > > Is there a way to use a boolean function as a join condition? If not, is it > easy to develop this capability. I have implemented some spatio-temporal > functions as part of my master thesis but for bench-marking, I need to have > join capability. > > e.g. > > SELECT A.a,B.b > FROM A JOIN B OVER overlap(A.a,B.b) > > -- > > Regards > Faisal Moeen
