FAQ
Hi,

I've been playing around with xapian, and I have a couple of questions.

I know that QueryParser and TermGenerator are matched in the way they come up
with terms, based on stemming and all that. They prefix "Z" to the start of a
stemmed word.

I'm trying to come up with a solution to index and retrieve exact documents
based on their names. And I was thinking that I may use my own prefix to make
sure that page comes up as 100% (or at least on the first page).

Does anything else use prefixes? I haven't played around with the DateRange
things, but do they use specific prefixes?

I don't want to conflict with an existing prefix. I also may use a
multi-character prefix to avoid subsets and other things.

Cheers.

Search Discussions

  • Olly Betts at Jun 15, 2007 at 2:23 am

    On Fri, Jun 15, 2007 at 01:10:16AM +0000, David wrote:
    Does anything else use prefixes? I haven't played around with the DateRange
    things, but do they use specific prefixes?
    The DateValueRangeProcessor approach uses values rather than terms, so
    no term prefixes are involved. Omega can use a term-based approach to
    date ranges, and that uses D, M, and Y, but now also offers a
    value-based approach. I suspect that the term-based approach will be
    phased out eventually (but currently I've not benchmarked the two and
    I'd like to check that the new approach works better before removing
    the old one!)

    Prefixes can be used for probabilistic fields (e.g. to allow searching
    within the title of a document), and for boolean filters (e.g. to allow
    searches to be restricted to a particular document type).

    This documents the prefixes which are standardly used:

    http://svn.xapian.org/trunk/xapian-applications/omega/docs/termprefixes.txt?view=markup

    Cheers,
    Olly
  • Dmorris at Jun 15, 2007 at 2:32 am
    Hmmm... I think that I am now more and less confused at the same time.

    The prefix things and all those things makes sense. But what I now don't
    understand is the difference between "term" and "value".

    Can you point me out to where would be a good place that explains the
    differences?

    Cheers.



    Olly Betts wrote:
    On Fri, Jun 15, 2007 at 01:10:16AM +0000, David wrote:

    Does anything else use prefixes? I haven't played around with the DateRange
    things, but do they use specific prefixes?
    The DateValueRangeProcessor approach uses values rather than terms, so
    no term prefixes are involved. Omega can use a term-based approach to
    date ranges, and that uses D, M, and Y, but now also offers a
    value-based approach. I suspect that the term-based approach will be
    phased out eventually (but currently I've not benchmarked the two and
    I'd like to check that the new approach works better before removing
    the old one!)

    Prefixes can be used for probabilistic fields (e.g. to allow searching
    within the title of a document), and for boolean filters (e.g. to allow
    searches to be restricted to a particular document type).

    This documents the prefixes which are standardly used:

    http://svn.xapian.org/trunk/xapian-applications/omega/docs/termprefixes.txt?view=markup

    Cheers,
    Olly
  • Olly Betts at Jun 27, 2007 at 9:13 pm

    On Fri, Jun 15, 2007 at 11:32:11AM +1000, dmorris wrote:
    The prefix things and all those things makes sense. But what I now don't
    understand is the difference between "term" and "value".

    Can you point me out to where would be a good place that explains the
    differences?
    See section "Accessing a document" here:

    http://www.xapian.org/docs/overview.html

    Cheers,
    Olly

Related Discussions

Discussion Navigation
viewthread | post
Discussion Overview
groupxapian-discuss @
categoriesxapian
postedJun 15, '07 at 2:10a
activeJun 27, '07 at 9:13p
posts4
users2
websitexapian.org
irc#xapian

2 users in discussion

Olly Betts: 2 posts Dmorris: 2 posts

People

Translate

site design / logo © 2022 Grokbase