> Ah... this is the real motivating point it seems. Well, not really. A lattice based on a single table is still really useful.
On Mon, May 4, 2015 at 7:20 PM, Ted Dunning <[email protected]> wrote: > On Mon, May 4, 2015 at 11:13 PM, Julian Hyde <[email protected]> wrote: > >> Calcite also lets you define materialized views outside of a lattice, >> and it does its best to match queries to such materialized views, but >> does less well. In particular, It doesn't match join queries well. The >> search space for unifying a materialized view containing an N-way join >> to a query containing an N-way join is exponential in N, so it doesn't >> try. >> > > Is it possible to use sub-query structure to hint this? > > > >> If you define a materialized view within a lattice, the structure >> provided by the lattice allows join queries to be matched very >> quickly. >> > > Ah... this is the real motivating point it seems.
