The
Nrcs
parameter sets the list of stratified dimension
values for use during refinement ranking by the MDEX Engine.
The
Nrcs
parameter groups specified dimension values into
strata. The stratified dimension values specified in the parameter are
delimited by semi-colons (;) and each stratified dimension value is in the
format:
stratumInt,dimvalID
where dimvalID is the ID of the dimension value and stratumInt is a signed integer that signifies the stratum into which the dimension value will be placed.
The
Nrcs
parameter thus provides a mapping of dimension
values to strata in the query:
You can define as many strata as you wish, but keep the following in mind:
For boosted strata (i.e., strata defined with a positive >0 integer), numerically-higher strata are boosted above numerically-lower strata. For example, dimension values in strata 2 are boosted above dimension values in strata 1.
Dimension values within a specific stratum are returned in an indeterminate manner. For example, if the dimension values with IDs of 5000 and 6000 are assigned to a stratum, it is indeterminate as to which dimension value (5000 or 6000) will be returned first from a query.
Ties will be broken with whichever type of dynamic refinement ranking is in use (alphabetically or dynamically).
Note that a dimension value will be stratified in the highest strata it matches, so boosting will have priority over burying.