> Windows Vista, then called by its codename "Longhorn", given to developers at the Microsoft Professional Developers Conference in 2003, included WinFS, but it suffered from significant performance issues

Odd, I did tried out a few Longhorn builds. Not knowing if they were shipped with WinFS, but in my case the "performance issues" of the system was caused by increased RAM demand (I only had 512MB RAM at the time).

The referenced sourced by Paul Thurrott from winsupersite.com mentioned:

    > (https://web.archive.org/web/20070702131752/http://www.winsupersite.com/showcase/winfs_preview.asp)
    >
    > it was pretty clear that WinFS wasn't ready for prime time. As one might expect, WinFS suffered from huge performance issues and simply bogged down the regular builds. And while WinFS was indeed included with the WinHEC 2004 Longhorn build that Microsoft shipped in May 2004, Microsoft was surprisingly quiet about WinFS at that time. A few months later, we found out why.

One old discussion on the subject suggested:

    > (https://ask.metafilter.com/129685/Why-did-WinFS-fail)
    >
    > posted by @troy at 3:03 PM on August 9, 2009:
    > I read that as "slow as a wee lassie on anything less than 16GB and quad dual-cores". They're waiting for PCs to be fast enough.
    >
    > posted by Ptrin at 7:13 PM on August 10, 2009:
    > Because Longhorn was cancelled. The WinFS project was a part of Longhorn, and when Longhorn died, WinFS did as well

But the exact cause for the issues remain undisclosed. Don't you just like these close sourced hypes? LOL

I think WinFS failed for the same reason the Cairo Object filesystem before it did. Microsoft required WinFS to use their SQL server rather than implementing the limited structures directly in the filesystem.