Drill also makes use of hash tables and hash partitioning. I’m not sure what was the purpose of your question. Are you carrying out a survey?
Julian > On May 1, 2016, at 5:22 PM, Ted Dunning <[email protected]> wrote: > > Drill doesn't use any such data structures in itself. The emphasis has been > on being correct first with the option of introducing approximations later. > > That said, you can definitely define aggregators yourself. Last I checked, > however, user defined aggregators are single level ... that means that > everything that gets aggregated has to go through a single function which > definitely limits scalability. This was several months ago, though, so > things may have improved by now. > > Perhaps somebody can comment on whether multi-level user-defined > aggregators are possible? > > > > On Sat, Apr 30, 2016 at 8:32 AM, Edmon Begoli <[email protected]> wrote: > >> Is Drill using any of the probabilistic data structures [1], and if so - >> which ones and how? >> >> Thank you, >> Edmon >> >> 1. Probabilistic Data Structures - >> https://en.m.wikipedia.org/wiki/Category:Probabilistic_data_structures >>
