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Cleaning cache folders - point?
There's few (cache) folders in Opera, which 3rd-party cleaners can empty in addition to the general browser website cache, for example: indexed databases, application cache, local storage, WebSql databases, GPU cache and file system. I know the general browser cache is good to empty quite often, but is there really point of cleaning those other cache locations, at least very often? Can they actually work like prefecth and speed up things, when regurlarly using same sites?
Just need to add, that you SHOULDN'T clear FILE SYSTEM folder. I tested to clear it and one side effect was, that Adguard stopped working and needed to reinstall it. Adguard and likely some other extensions store permanent data in that folder. So leave that folder alone.
Local storage is used by web apps for data that is supposed to be available offline - theoretically. In practice it is also used to supplement a site's cookies (cookies are limited in total size per site). So ... sites that remember what you typed in their forms, will probably forget it if you dump local storage, and webmail will have to re-download messages you've already seen and so on. You may be better off managing it in the browser (unless you're one of these people who has an external program delete all your cookies already).
I'd think GPU cache should be cleared on startup or shutdown automatically, but I really don't know. Obviously don't clear it (or anything) while the program is running - while it may be actively in use - but otherwise it should be safe to empty.
Indexed databases may include Opera's own databases - bookmarks, cookies, etc. (just the indexes of course) ... I would not touch it. The others I don't know.
Ok. Well, IndexedDB folder is cleaned (except startpage index) when i close the browser. Some entries in Local Storage is also cleaned at browser shutdown, while some data is left. CCleaner cleans some more of those LS entries, but still leaves some. There's around 10 LS entries left after browser close and CCleaner. IndexedDB and Local Storage entries seems to be very small in size, so i doubt it speed up things leaving them. I have set Opera to keep local data until i close the browser, so it can be reason why some is deleted at browser shutdown.
GPU cache does not seem to auto-cleared by Opera, but CCleaner cleans it by default.
EDIT: CCleaner cleans 0 size local storage entries, which are left by Opera.
Also, i did a test and manually deleted all Local Storage files, since there seemed to be some suspicious and probably obsolete entries. I was right. Most of those LS entries were/are extension settings files. Deleting all LS entries, reset settings for my extensions, and the entries were recreated. But some entries were not recreated, since they (most likely) were leftovers of REMOVED extensions. So if you have removed lot of extensions, clearing (and thus refreshing) Local Storage would be a good idea. But remember, it RESETS settings for current extensions!!
Automated cleaners are just that - automatic and not always a good idea.
I've used Crap Cleaner before on Windows. I usually don't let it clean any of my browser's junk. I just leave that stuff there - sometimes I'll delete the temp files manually but disk space is plentiful and it doesn't seem to impact it. If someone has physical access to my computer then my temp files are the least of my security concerns.
Just figured I'd share my experiences and thinking process.
Just wonder if file "QuotaManager" is safe to delete. I opened it in notepad and noticed it contains entries of some sites i have visited. I have understood QuotaManager keeps track of storage size limits etc..?