With this example calculation, it's plausible that a tree structure can easily be much faster than the flat filesystem, like 2000 times as fast. We could als use three levels with 100 entries. To find one, we need to read 500 names on average on each level, 1000 in total.
In a tree structure, we could use two levels of the tree by splitting the files into 1000 directories, with 1000 files each. To find a file, about half of the file names must be read, on average.įor 1000000 files in a flat filesystem, that means we need to read 500000 names. The problem is that a directory listing is going through the whole list - because no tree is used inside the directory. That all is not relevant for only thousands of files, but for hundredthousands in each of 100 directories, you better not put them all in a flat filesystem, or all in one directory. The performance of listing directories depends on the file count of the directory.Įven in hierarchical filesystems, it can be a problem to list files in a directory to delete them, if they are many. The two main types of differences are in CPU time, and in memory use.Īnother type that could be relevant here is the complexity of implementation.
With flat filesystems that have only one place that contains all files, similar to a single directory with no subdirectories. We compare hierarchical filesystems with a tree structure of directories,
We want to compare filesystem structures looking for non-aesthetic differences.
0 kommentar(er)
