Databricks Online Feature Table is in public preview , And we have some questions on this 

1) What storage is being used for Online Feature table's Data. Our offline feature table is stored in Unity Catalog managed S3 bucket (Customer AWS ). Does online feature table use databrick's internal storage or customer's Cloud ?

2) https://www.databricks.com/product/pricing/online-tables How we can get the storage cost information. For capacity units we can use billing_origin_product = ONLINE_TABLES.

3) Are there explicit charges for data refresh from offline source table to online table "Snapshot or Triggered sync mode (data transfer)"  ?