So, prefix queries against keyword fields are considered expensive. However, the article I referenced in my initial post ( Find strings within strings faster with the Elasticsearch wildcard field | Elastic Blog ) describes prefix queries on keyword fields as 'fast' and on wildcard fields as 'not quite as fast'. This appears contradictory.
Why there is such a discrepancy in the performance descriptions of prefix queries on keyword fields? Is there a specific context or configuration where prefix queries on keyword fields can indeed perform efficiently?
Additionally, I am curious about why the index_prefixes option is not available for keyword fields, whereas it is available for text fields. What is the technical reason behind this?
Thank you for any insights or clarifications.