Is scan cache date dependent?

priestlucas123 · 2017-06-09T19:22:14.000Z

Does anyone know if the scan cache is only valid for the day it is created? Reason I ask:

(for each test, my computer is turned off, back on, wait 5 minutes, no programs run) then:

test 1) run Full scan with setting “store data about scanned files in the persistent cache” checked; takes 30 minutes
test 2) on same day as test 1, run Quick scan with setting “speed up scanning by using the persistent cache” checked; takes 2.5 minutes
test 3) on next day, run Quick scan with same settings at test 2 but scan now takes 12 minutes

to me this shows that the scan cache is date dependent and not release dependent

I have tried doing a repair, and even uninstalling (safe mode, avastclear) and reinstalling but no change. No other antivirus program ever installed on computer.
I am running Windows 7, SP1, Avast 2294 free version.

DavidR · 2017-06-09T19:43:37.000Z

Does the information in the relating to the caches in the File System Shield > Customise > Advanced not answer your question. As far as I’m aware these explanations are the same for on-demand scans.

One setting in the scans that is off by default may not be doing you any favours.

AvastUI > Protection > Antivirus > Select your scan/s settings > Performance - Persistent cache and ensure that you have the ‘Store data about scanned files in the persistent cache’ option enabled.

There are a number of virus definitions updates a day, so this could have an impact on the Transient cache. What I don’t know is how the streaming updates would be effected by these as they occur very frequently.

priestlucas123 · 2017-06-09T19:46:07.000Z

The File System Shield advanced options are checked, but does this persistent cache mean the same as the one used by the Full and Quick scans?

priestlucas123 · 2017-06-09T19:52:02.000Z

As to suggestion about virus definition updates and streaming updates affecting persistent cache used by scans, if this was the reason the cache is cleared or not used then why have it since there are several updates a day and a lot more streaming updates which would make cache only valid for an hour or so?

DavidR · 2017-06-09T19:59:02.000Z

priestlucas123 post:3:

The File System Shield advanced options are checked, but does this persistent cache mean the same as the one used by the Full and Quick scans?

As far as I’m aware there is only one Transient and one Persistent cache on the system. Personally I believe it makes sense to only have one Transient and one Persistent cache for all scans on-demand or on-access.

To have one for each on-demand scan would be a mess as they would be at lease four more Transient and Persistent caches (more if you had custom scans) and of course another for the on-access File System Shield scanning.

DavidR · 2017-06-09T20:04:24.000Z

priestlucas123 post:4:

As to suggestion about virus definition updates and streaming updates affecting persistent cache used by scans, if this was the reason the cache is cleared or not used then why have it since there are several updates a day and a lot more streaming updates which would make cache only valid for an hour or so?

I have already said what I know/suspect about the Virus Definition Updates/Streaming updates. I can only go on how things used to be before streaming updates were introduced. Plus the fact that the wording in the Use Transient caching paragraph haven’t included anything about streaming updates.

For me if the transient cache was reset after each streaming update, then it would make it redundant.

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