The ttl (time-to-live) Parameter in Feature Views
The value of ttl
affects the availability of feature data in the online store
and the generation of training feature data.
ttl
is a Batch and Stream Feature View parameter, as well as a Feature Table
parameter.
For a Feature View that contains one or more Aggregation
s, the Feature View's
ttl
value is implicity set to the aggregation_interval
value.
Effect of ttl
on the availability of feature data in the online store​
ttl
specifies the amount of time, prior to the current time, that feature data
is available in the online store. Feature data with timestamps earlier than the
current time minus the ttl
value will expire.
Effect of ttl
on the generation of training feature data​
ttl
specifies the maximum amount of time prior to the timestamp of a training
event, that data in a Feature View's data source is available for generating
feature data for the training event.
Lower ttl
values will allow get_historical_features()
to run more
efficiently in some cases, because the amount of training data generated will be
reduced.
ttl
has no effect on deletion of feature values from the offline store. To
delete values from the offline store, use the
delete_keys() method.