Transactional filesystems [LWN.net]

Transactional filesystems

Posted Mar 20, 2009 20:54 UTC (Fri) by butlerm (subscriber, #13312)
In reply to: Transactional filesystems by alvherre
Parent article: Better than POSIX?

PostgreSQL is not a filesystem. If it was pretending to be one, it would
accomplish what it does by "meta-data" undo, where the meta data of the
higher level filesystem was native to PostgreSQL (i.e. stored in table
rows), as opposed to the completely separate and irrelevant meta data of
the lower level filesystem PostgreSQL was running on top of.

So of course you can implement meta data undo on any filesystem you please,
just as long as the meta data you are referring to is not the meta data of
the filesystem itself.

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Transactional filesystems

Posted Mar 21, 2009 18:00 UTC (Sat) by nix (subscriber, #2304) [Link]

I don't see why you can't use MVCC for filesystems, since MVCC could be
regarded as a means of mixing the undo log into the data store itself,
eliminating it as a separate entity.

(As for vacuuming, do it incrementally and the data volume pretty much
doesn't matter; you just work through it bit by bit. PostgreSQL scales to
silly data volumes already...)