Any store that does not support expiration should not be configurable as having a default expiration. Note a user may still invoke the overridden methods to supply an expiration value.

Remainder of description details sql store, since it is our only store currently that does not support expiration.

The SQL Store is used to read information from an existing user database table. There is no notion of expiration available to Infinispan. Therefore we should not allow a user to configure a sql store that can write with expiration since it is possible to lose the expiration information if the entry ever leaves memory or the node is restarted.

A user should still be able to configure the sql store as read only with expiration. This is a very valuable use case since expiration will remove entries from memory, forcing a refresh of the data from the back end database. Basically used to guarantee cache freshness.

A user should use the JdbcStringBasedStore if they want a database solution with expiration and writes.