Hello,
Can you tell me what’s the diference between the advanced ante-memorization and the permanent ante-memorization ?
Thank you very much 
And I’ve an other question :
When you activate the permanent ante-memorization, if Avast! scan a healthy file, after Avast! will recognize the file as clean even if, after an update, the file is a malware in reality. No ?
Thank you
I hope this is OK as there is likely to be differences in the French and English terms.
avast 5 - Scan Transient and Persistent caching to speed scanning.
Use transient caching - if transient caching is used, a file that has been scanned, and in which no infection was detected, will not be scanned again the next time it is accessed.However, this is only valid until the next virus definitions update, as the file may contain an infection that was not previously detected but which may be detected based on the new virus definitions. Also, information that the file is clean will only be stored in the computer’s operating (temporary) memory.
This means that when the system is restarted the information will be lost, therefore the file will also be scanned again the next time it is accessed after a system restart. This box is checked by default; if you want files to be scanned every time they are accessed. this box should be unchecked.
Use persistent caching - if persistent caching is used, the information about the scanned file is stored in the permanent memory.
This means it is not lost after a system restart and it is also not affected by virus definition updates. Consequently, persistent caching is suitable only for files which are guaranteed not to contain any virus infection e.g. operating system files, files signed by trusted publishers, or other files covered by the avast! whitelist.
This box is checked by default; if you want all files to be scanned regardless of their trust status, this box should be unchecked.
lol in fact, I think there’s a difference between french and english translation ;D but this is what I talking about : the caching.
Thank you for your answer, so if I understand well, persistent caching is based on a whitelist which we can’t modify, it’s a cloud list. isn’t it ?
You’re welcome.
That is correct you can’t modify the Persistent cache, it is based on several things (as in my quote, OS files, Digitally Signed files) and whitelist is one of them.
The list isn’t currently a cloud list it is updated through the virus definitions updates. (I don’t know what the future plans for avast are on that, but cloud is one of the future developments).
OK, and this system of caching is the same for the real time protection of files and the different kind of scan, like the fast scan ?.. Because the choice between a transient and persistent caching is also available in the real time protection of files.
And to finish, what would advice me to do ?
Thanks a lot
I presume it acts the same way in the File System Shield (the only shield with the Advanced tab), it isn’t so much a choice between both as you can have both selected.
Since the two caches work in a different way then there would be no problem in having both options enabled, which I believe is the default option. This would prevent constant scanning of a file that is regularly in use.
OK, OK, so thank you very very much for having answer my questions !
To Conclude : If one of the healthy file which is in the whitelist become infected, Avast! will not detect it as a virus ?
See you on the forum
No problem, glad I could help.
A belated welcome to the forums.
Lol you posted your answer during I’m modifying my post to add a last question :
We’re fast on the avast forums ;D
The file will have changed, essentially if it is a file which is digitally signed, it will no longer have a valid signature. The other major point is that the info about said files is recorded, so a change would be noticed:
Use persistent caching - if persistent caching is used, [i]the information about the scanned file is stored in the permanent memory.[/i]
I don’t believe they are permanently excluded from scans but a check could be made against the stored information to ensure it remains the same. I don’t believe avast wouldn’t have considered this fully before its addition to the cache, etc.
This information is my best guess (other than the quotes) as I’m just an avast user like yourself, but I have been using avast for over six and a half years and the new avast 5.0 for ten months.
BIG thanks !
So, I am going to rely on your experience 
See you on The Avast! forum
(This time I say Goodbay for real )
Bye for now ;D