-Re: Language support
Benson Margulies 2008-03-20, 16:20
Unless you can come up with language-neutral tokenization and stemming, you
a) know the language of each document.
b) run a different analyzer depending on the language.
c) force the user to tell you the language of the query.
d) run the query through the same analyzer.
On Thu, Mar 20, 2008 at 12:17 PM, David King <[EMAIL PROTECTED]> wrote:
> > You may be interested in a recent discussion that took place on a
> > similar
> > subject:
> > http://www.mail-archive.com/[EMAIL PROTECTED]/msg09332.html
> Interesting, yes. But since it doesn't actually exist, it's not much
> I guess what I'm asking is, if my approach seems convoluted, I'm
> probably doing it wrong, so how *a*re people solving the problem of
> searching over multiple languages? What is the canonical way to do this?
> > Nicolas
> > -----Message d'origine-----
> > De : David King [mailto:[EMAIL PROTECTED]]
> > Envoyé : mercredi 19 mars 2008 20:07
> > À : [EMAIL PROTECTED]
> > Objet : Language support
> > This has probably been asked before, but I'm having trouble finding
> > it. Basically, we want to be able to search for content across several
> > languages, given that we know what language a datum and a query are
> > in. Is there an obvious way to do this?
> > Here's the longer version: I am trying to index content that occurs in
> > multiple languages, including Asian languages. I'm in the process of
> > moving from PyLucene to Solr. In PyLucene, I would have a list of
> > analysers:
> > analyzers = dict(en = pyluc.SnowballAnalyzer("English"),
> > cs = pyluc.CzechAnalyzer(),
> > pt = pyluc.SnowballAnalyzer("Portuguese"),
> > ...
> > Then when I want to index something, I do
> > writer = pyluc.IndexWriter(store, analyzer, create)
> > writer.addDocument(d.doc)
> > That is, I tell Lucene the language of every datum, and the analyser
> > to use when writing out the field. Then when I want to search against
> > it, I do
> > analyzer = LanguageAnalyzer.getanal(lang)
> > q = pyluc.QueryParser(field, analyzer).parse(value)
> > And use that QueryParser to parse the query in the given language
> > before sending it off to PyLucene. (off-topic: getanal() is perhaps my
> > favourite function-name ever). So the language of a given datum is
> > attached to the datum itself. In Solr, however, this appears to be
> > attached to the field, not to the individual data in it:
> > <fieldType name="text_greek" class="solr.TextField">
> > <analyzer class="org.apache.lucene.analysis.el.GreekAnalyzer"/>
> > </fieldType>
> > Does this mean there there's no way to have a single "contents" field
> > that has content in multiple languages, and still have the queries be
> > parsed and stemmed correctly? How are other people handling this? Does
> > it makes sense to write a tokeniser factory and a query factory that
> > look at, say, the 'lang' field and return the correct tokenisers? Does
> > this already exist?
> > The other alternative is to have a text_zh field, a text_en field,
> > etc, and to modify the query to search on that field depending on the
> > language of the query, but that seems kind of hacky to me, especially
> > if a query may be against more than one language. Is this the accepted
> > way to go about it? Is there a benefit to this method over writing a
> > detecting tokeniser factory?