@BaoTranHuyDuc Please read the docs for Enterprise Search:
OOTB - rasa uses FAISS as the vector DB. If you use the OOTB functionality, it is important to know:
- it only accepts text files
- customisation is limited. For example, you currently cannot customize chunk size, relevancy score. You can choose the embedding model by setting it in the config.yml (see here for more details).
If you want to customise the ETL of the source data more, you will have to build your own ETL pipeline and use an external vector DB.