I've always been annoyed how searching a few hundred thousand NTFS records for a filename containing some arbitrary text takes a relatively long time - even using specialized tools like FileLocator Pro which I believe directly scan low-level structures like the MFT - while I can do an equivalent search in a SQL database in milliseconds. I wish filesystems like that one had vastly more performant indexing structures for the metadata (without relying on add-on layers that defer indexing and - at least in my experience - tend to break down or be out of date or obfuscate files they think you don't care about - I'm looking at you, Windows Search).