Feast uses online stores to serve features at low latency. Feature values are loaded from data sources into the online store through materialization, which can be triggered through the materialize command.
The storage schema of features within the online store mirrors that of the original data source. One key difference is that for each entity key, only the latest feature values are stored. No historical values are stored.
Here is an example batch data source:
Once the above data source is materialized into Feast (using feast materialize), the feature values will be stored as follows:
Features can also be written directly to the online store via push sources .