Hi Milinda, For example, in Logical planning, Planner might decide using an INNER-JOIN is cheaper than using a FILTER on top a CARTESIAN-JOIN.
Then later in Physical Planing, it further chooses an "implementation" of this JOIN, (e.g., HASH-JOIN v.s. MERGE-JOIN) On Fri, Sep 4, 2015 at 11:05 AM, Julian Hyde <[email protected]> wrote: > Yes, Drill’s 3 layer architecture makes sense. The only thing I’d have > done differently is to put all 3 in the Calcite algebra, whereas Drill has > (I believe) a different physical algebra. > > > On Sep 4, 2015, at 11:02 AM, Milinda Pathirage <[email protected]> > wrote: > > > > Thanks Ted. > > > > Milinda > > > > On Sun, Aug 30, 2015 at 12:52 AM, Ted Dunning <[email protected]> > wrote: > > > >> Milinda, > >> > >> Factoring the version from SQL to an actual execution plan has a few > >> benefits. One of the biggest is that the logical plan doesn't vary if > the > >> cluster size or shape or locality changes, but the physical plan does. > >> This allows the SQL => logical translation and optimization to be > >> developed, tested and debugged independent of the cluster used. > >> > >> > >> > >> On Sat, Aug 29, 2015 at 5:36 PM, Milinda Pathirage < > [email protected]> > >> wrote: > >> > >>> Hi devs, > >>> > >>> Does anybody know the reason behind having a Drill specific logical > plan > >>> layer (DrillRel) and a physical plan layer (Prel)? > >>> > >>> Thanks in advance > >>> Milinda > >>> > >>> > >>> -- > >>> Milinda Pathirage > >>> > >>> PhD Student | Research Assistant > >>> School of Informatics and Computing | Data to Insight Center > >>> Indiana University > >>> > >>> twitter: milindalakmal > >>> skype: milinda.pathirage > >>> blog: http://milinda.pathirage.org > >>> > >> > > > > > > > > -- > > Milinda Pathirage > > > > PhD Student | Research Assistant > > School of Informatics and Computing | Data to Insight Center > > Indiana University > > > > twitter: milindalakmal > > skype: milinda.pathirage > > blog: http://milinda.pathirage.org > >
