What does Field.Index.NOT_ANALYZED_NO_NORMS mean

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 an开发者_Python百科d field length normalization ?

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.