Re: User tag design for read-only index

[Chris Hostetter <ho...@fucit.org>]

: The behavior I would like is identical to 'tagging' each document with the
: list-id/user/order and then using standard faceting to show what lists
: documents are in and what users have put the docs into a list.
: 
: But - I would like the main index to be read only.  The index needs to be
: shared across many installations that should not have access to other users
: data.
: 
: Any thoughts on how this might be possible?  Off hand, it seems like manually
: filling an un-inverted field cache might be a place to start looking.  Perhaps

the read only requirement makes this a particularly interesting problem 
... off hand i think you're right about wanting to maintain the tags 
explicitly in an UnInvertedField -- but you'll still need some sort of 
persistent storage for that.  you'll also need a way to filter docs by 
tag, which means maintaining an un-un-inverted index of the tags as well.

if your index truely is 100% read only, then you can take advantage of the 
internal docIds, in your main index ... which will make it a lot easier to 
build your UnInvertedField and to build up a DocSet for filtering based on 
the results of a query to your tag index ... but i suspect what you really 
mean is "the index will be updated much less frequently then the tags, and 
it will be shared by multiple applications so i can't make any 
modifications to it as part of hte tagging system." .. which makes things 
harder.

at the end of the day, the biggest deciding factor in picking a solution 
really comes down to the age old question: what turn arroundtime do you 
need between adding data (tags) and returning that data 
(facting/filtering) ? ... because if you're allowed a lot of lag, you have 
a lot more options.


-Hoss