Per 4.1.7 Savedsearches.conf you should be able to specify the 'dispatch.ttl' param.
dispatch.ttl = <integer>[p] * Time to live (in seconds) for the artifacts of the scheduled search, if no actions are triggered. * If an action is triggered the ttl is changed to that actions's ttl, if multiple actions are triggered * the maximum ttl is applied to the artifacts. For setting action's ttl refer to alert_actions.conf.spec * If the integer is followed by the letter 'p' the ttl is interpreted as a multiple of the scheduled search's period. * Defaults to 2p.
Thank you, Dave. I asked because it is not clear whether this setting can be used on a per-search basis. I'll test it and report back for future reference.
Yes. In the case of savedsearches.conf all settings can be set per stanza "saved search" name.
I've had issues with getting this to work. Despite setting "dispatch.ttl = 604800" for specific alerts, I still have search artifacts that report "expired" after a couple of days. I'll file a ticket.
This is no longer an issue in version 4.2 where one can now specify a ttl per search.