You need the columnar store for both training data and batch inference data. If you have a batch ML system that works with time series data, the feature store w

You need the columnar store for both training data and batch inference data. If you have a batch ML system that works with time series data, the feature store will help you create point in time correct training data snapshots from the mutable feature datab(no future data leakagae), as well as batch inference data. For real-time ml systems, it give uou row oriented retrival latencies for features. Most importantly, it helps modularize your ML system into feature pipelines training pipelines, and inference pipelines. No onolithic ML pipelines.