Hi,

In MERGE subscriptions the snapshot length is always 1, only the latest data per each item/field is stored.
In COMMAND subscriptions the snapshot length is variable, the latest data per each key/field of each item is stored.
In DISTINCT subscriptions the snapshot length is set by the MetadataProvider implementation (see
http://www.lightstreamer.com/docs/...adataProvider.html#getDistinctSnapshotLength(ja va.lang.String)
)

The snapshot for an item is hold until there is someone subscribed to that item, there is no way to set a time-based expiry.