Dynamic field types are field types that act as proxies to other field types. The choice of the field type to use is done on a per document basis and is dependent of the values of the document's fields.
The use case that led us to this feature is the indexation of documents in different languages. We use a specific analyzer for each language but want to index semantic information that is not specific to the language. For example, we would add in the index the semantic tag {co:Paris} for the expressions "Paris", "capital city of France", "the city of lights" in English and "Paris", "capitale de la France", "la ville lumière" in French. This allows us to provide advanced functionalities such as semantic and cross-lingual search. To do so in SOLR, we chose to index texts written in different languages in the same field, while analyzing them with different analyzers. Hence the proposition of a new feature that respond to this need: Dynamic Field Types. The idea of this new field type is to act as a proxy to other field types. Depending of the values of some fields of the document to index, it chooses the correct field type to use. In our situation, we use it to choose the correct language dependent field type based on the value of the field named "language". It is configured with a config similar to the following: <fieldtype name="french_ft" ...> ... </fieldtype> <fieldtype name="english_ft" ...> ... </fieldtype> <dynamicFieldType name="multilanguage"> <fieldtypes> <fieldtype condition="language:fr" name="french_ft"/> <fieldtype condition="language:en" name="english_ft"/> <fieldtype condition="*:*" name="english_ft"/> </fieldtypes> </dynamicFieldType> The last condition is used as a catch-all if preceding conditions are not met. What do you think of this feature? Best regards, Nicolas Dessaigne