Hi. I am trying to understand an option in Avast! Anti-Virus Free.
In the main settings, under “Advanced”, it talks about Transient Caching, which says that it stores the info about a file and will not scan it again, until a reboot, or a definition update. So when a definition update happens, it will be scanned again, in case the new definition is able to detect a virus that the last one didn’t know about.
Okay, except for the reboot part, that sounds good! 
But the Persistent Caching options says that it stores the info in permanent memory and so, file scanning is not affected by definition updates and it won’t scan it again when it’s opened, even if a definition update occurs.
The storing permanently thing sounds good to a point, but not the part about it not scanning it again, if there is a definition update.
The first thing, is that these two sound contrary to each other, but it says for both that they are checked by default. I don’t understand that!
Second, what will happen then with both checked?
It sounds like a good thing to have it checked again if there’s a definition update, but I also want it to store it at least semi-permanently, which means it would be good to store it so that reboots don’t affect it, but definition updates do.
Is that what checking both accomplishes? If so, with all due respect, might I humbly suggest that a third option that says it stores it semi-permanently and reboots do not affect it, but a definition update will cause it to scan the file again when it’s opened be made available?
If this is what checking both of these options results in, it would be a lot less confusing this way, no?
Or do they NOT do that when they are both checked? If not, then why are they both checked, as they seem to contradict each other? What does it accomplish then?
And if they do not do that, then is there a way that I can accomplish it not being affected by reboots, but yet, being affected by definition updates?
Thanks!