Pradeep, I hope that we have the opportunity to teach this material again soon. In the meantime, I encourage you to read my blog posts here. For example, my post today is largely extracted from the section of the class on the limitations of vector search:

https://medium.com/@dtunkelang/llms-and-rag-are-great-but-dont-throw-away-your-inverted-index-741d33630b7f