Is your feature request related to a problem? Please describe.
The field name ttl used in FeatureView is misleading.
Time to Live (TTL) is a well known term that defines a mechanism to automatically expire database records. In Redis, for example, the command EXPIRE defines a time to live for a given key.
When I used that FeatureView.ttl configuration for the first time, I expected to set some expiration time (or TTL) for keys written into online stores. The documentation states something like this here.
The amount of time this group of features lives. A ttl of 0 indicates that this group of features lives forever.
However FeatureView's TTL is not used in that way. It's used to define start_date to extract data from offline store during materialization step here. The actual key ttl configuration used to expire entities is key_ttl_seconds at online store level here.
I had to explain this sometimes to different people because of this misunderstanding. I think this is also kind of mentioned here and here.
Describe the solution you'd like
My suggestion is renaming this field to something like materialization_lookback_interval, lookback_interval or lookback_delta since this is the actual meaning of this configuration as far as I understand. Also update docs accordingly.
Is your feature request related to a problem? Please describe.
The field name
ttlused inFeatureViewis misleading.Time to Live (TTL) is a well known term that defines a mechanism to automatically expire database records. In Redis, for example, the command
EXPIREdefines a time to live for a given key.When I used that FeatureView.ttl configuration for the first time, I expected to set some expiration time (or TTL) for keys written into online stores. The documentation states something like this here.
However FeatureView's TTL is not used in that way. It's used to define
start_dateto extract data from offline store during materialization step here. The actual key ttl configuration used to expire entities iskey_ttl_secondsat online store level here.I had to explain this sometimes to different people because of this misunderstanding. I think this is also kind of mentioned here and here.
Describe the solution you'd like
My suggestion is renaming this field to something like
materialization_lookback_interval,lookback_intervalorlookback_deltasince this is the actual meaning of this configuration as far as I understand. Also update docs accordingly.