Hello:
I cannot find info on how to empty the MD5 cache. Can it be done?
Thanks,
Hans L
There isn't a button to clear the cache, but it uses a tiny amount of data per file. Is there a reason you need to?
It could be done using a script or similar if you really need it.
Leo, I think I misunderstood what "Use MD5 cache" means. I now believe I understand that when you use MD5 checksum, the result is always cached, and when you want to use the cached result, you check "Use MD5 cache". Is taht right?
Hans L
From the manual:
Use MD5 cache : Use the MD5 checksums cache for large files located on NTFS partitions. If a large file's checksum is calculated it will be cached, and the cached value used in the future if the file doesn't appear to have changed.
Leo, with all due respect, this text, which I have read several times, does not explain to me under which circumstances the MD5 cache is created. And how large is a large file?
Hans L
The MD5 cache is created when MD5 caching is turned on and when the a file's MD5 is calculated (1), and where the file is large enough that re-calculating the MD5 would take a long time (2).
1: f using the Duplicate Finder in MD5 mode, MD5s are calculated when two or more files have the same size. If a file has a unique size then you know no other file is a duplicate of that file, as the data can't be the same if the size isn't.
2: For very small files, there's no point caching the MD5 as it can be recalculated as fast as the cache could be read, and for very small files the size of the cached MD5 value could be a similar size to the file itself.
Why do you care about any of this? The cache uses a few bytes of disk space per (large) file. What is the reason for wanting to clear it or caring about whether it is there or not? Is it causing a problem?
Okay, Leo, thank you.
Now, let me explain. I checked a folder with a LOT of subfolders and a LOT of files for duplicates, and in a blink of an eye, the check was made. It seemed too fast for me, and I wondered if a cache was used that might have caused an MD5 recalculation not to take place. So I thought, let's empty the cache so I know I am starting fresh (you know how many times you get forum and other advice of "Empty the cache" when you get results that do not seem correct). But I assume from your writing that one will not have to worry that the cache is giving false results in searching for duplicate files in Dopus.
Regards,
Hans L
I wouldn't worry about the cache. If you think the results are not correct, look for some examples and let us know what they are, and how the Duplicate Files panel is configured.
The cache also will not be used if you haven't turned on the option to use the cache, so if you're worried it is causing a problem, just turn off that option and run the operation again. If the results are the same as before, you know the cache isn't a factor.
Thanks, Leo!
Hans