Expert: attributes streaming definition for indexing facets
Steaming of facets attributes is a low level indexing interface with Lucene indexing.
There are two types of category related streams:
- Category tokenizer stream handles tokenization for a single category,
e.g. for creating drill-down tokens.
- Category list tokenizer stream handles tokenization for multiple categories,
e.g. for creating a counting list token, representing all the categories of
a certain document.