views:

48

answers:

1

I know what does not_analyzed mean. In short the field will not be tokenized by specified Analyzer.

However, what does a NO_NORMS means? I see the documentation, but please explain me in plain English. what is index-time field and document boosting and field length normalization ?

+2  A: 

It disables the following features:

  • index-time field and document boosting: this means that the index will ignore any boosts you did to fields (AbstractField.setBoost) or documents (Document.setBoost). A matching token will always be worth the same.
  • field length normalization: this means that the index will ignore whether a matching token was in a short field (which should be more relevant) vs. a long field (less relevant). Again, a matching token will always be worth the same, no matter the length of the field.
martin
so in short a field marked as NO_NORMS does not affect ranking of result at all, is that what this mean?
Ankit Jain
This is inexact. If a field is marked as NO_NORM, term matches on it DO affect ranking. Just its boost and length do not.
Yuval F
I didn't mean that a matching term doesn't affect ranking, I meant that it does in the same magnitude, no matter the field's length.
martin