I am successfully using function_score to customize result scoring. Presently, I am setting
boost_mode="replace". But I'm wondering if it's possible to preserve the internal ES
_score field in someway before doing that replacement. I thought I could achieve this by adding a
script_field script that simply returns
_score, but it seems as though I cannot reference
_score from a
ExpressionScriptCompilationException[Unknown variable [_score] in expression]
Is there another way to achieve this?
Thanks for your help!