Using Relative Field Weighting to Customize Relevance Ranking in Amazon CloudSearch
You can assign weights to selected fields so you can boost the relevance
_score of documents with matches in key fields such as a
title field, and minimize the impact of matches in less important
fields. By default all fields have a weight of 1.
Field weights are set with the
fields option. You specify fields as an array of strings. To set the weight
for a field, you append a caret (
^) and a positive numeric value to the
field name. You cannot set a field weight to zero or use mathematical functions or
expressions to define a field weight.
For example, if you want matches within the
title field to score higher
than matches within the
plot field, you could set the weight of the
title field to 2 and the weight of the
plot field to
In addition to controlling field weights, the
fields option defines the
set of fields that are searched by default if you use the simple query parser or don't
specify a field in part of a compound expression when using the structured query parser.
For more information, see Search Request Parameters in the Search API Reference.
To reference the weighted relevance score in the definition of an expression, you use
_score. You can use the weighted
_score value in
conjunction with numeric fields, other expressions, and the standard numeric operators
and functions. For more information, see Configuring Expressions.