NAME
     lab 23 - annotating a file system

DESCRIPTION
     This lab was cut and pasted from my homepage. It is not new.

     i have tried out some experiments with annotating the
     filesystem; really, several iterations of the same idea. 

     my latest attempt is tickfs, which i think comes close to
     doug mcilroy's of a metadata file system.

     each file served by <b>tickfs</b> is a binary relation, the
     key is usually an absolute pathname, and the attribute is
     defined by the name of the relation.  each relation is also
     bi-temporal.  it's a historical record of changes to each
     key, value pair and it determines whether a key, value pair
     is true at a given time.

     adding metadata is simple
     	% echo ${quote i . /doc/sh.ms 'the inferno shell' } > /n/tickfs/desc
     	% echo ${quote i . /doc/sh.ms 'rogger peppe' } > /n/tickfs/author
     the dot indicates the current time, but any time represented
     as seconds since the epoch can be given.

     queries are pipelines
     	% 9ls sh.ms |taq /n/tickfs/author |taq -j /n/tickfs/desc
     the query uses the timestamp of the files to return the
     currently effective values for the attributes 'author' and
     'desc'.

     it relies on a disciplined user to maintain a single logical
     namespace and to keep it consistent with the namespace of
     keys within tickfs.  plan9 and inferno make it easy to alter
     the namespace; but the discipline of arranging a clear,
     consistent namespace is harder.

     an example that includes fossil is to bind a directory from
     dump over the logical namespace.  the currently effective
     values will likely vary over time, and so obtain different
     results from tickfs.
             % 9ls /doc |taq /n/tickfs/desc
             % bind /n/dump/2004/0101/doc /doc
             % 9ls /doc |taq /n/tickfs/desc

     also, i have tried indexing file contents within
     <b>tickfs</b>, so combinations of keyword search and named
     descriptors can be used
     	% search bug |taq /n/tickfs/author |grep caerwyn |taq /n/tickfs/desc

     tickfs runs on inferno, but lookfs, which is an earlier
     iteration using libstyx, is very similar and should run on
     plan9.

FILES
     The source for this lab is in the archive on my

                         Inferno Manual