Provide fast access to a subslice based on one or more group key
values.
The SliceIndex currently uses in-memory data structures, although
this will have to change eventually. A "group key value" is
defined as an (Int, RValue). The Int part corresponds to the key
in the sequence of transforms used to build the index, and the
RValue part corresponds to the value we want the key to have.
SliceIndex is able to create subslices without rescanning the
underlying slice due to the fact that it already knows which rows
are valid for particular key combinations. For best results
valueSlice should already be materialized.
Provide fast access to a subslice based on one or more group key values.
The SliceIndex currently uses in-memory data structures, although this will have to change eventually. A "group key value" is defined as an (Int, RValue). The Int part corresponds to the key in the sequence of transforms used to build the index, and the RValue part corresponds to the value we want the key to have.
SliceIndex is able to create subslices without rescanning the underlying slice due to the fact that it already knows which rows are valid for particular key combinations. For best results valueSlice should already be materialized.