Totally agree.Database with both row and column storage engine could help a lot.T hat's the reason OSSInsight like workload can run on top of TiDB easily, whether scan the whole table or scan part of the index.
Keeping low latency for an online data service with more than 5 billion records can be a challenge. Features like query the database with natural language(https://ossinsight.io/explore).This makes it easier for users to access the data without having to know SQL. But the generate SQL could be pretty heavy(many Full table scan and index scan).
Answers from AI could be wrong sometimes(close to 20%). The better database schema and purpose provide for AI, the better results you can get. This can help the AI better understand what you are asking it to do and improve the accuracy.