Xapian discuss - Nov 2006 - Unique Term Listings

Hi

I would like to retrieve a count of the number of entries per term  
for a particular query.
For example if I had a date term I would like to bring back the  
number of entries for each particular date.
Or if I had a category term I would like to bring back the number of  
entries for each category.
Is this possible to do in Xapian?

Many thanks in advance.

Martin

You want the "get_termfreq()" methods.

If you have a Xapian::MSet object, its get_termfreq() method will return
the term frequency for terms in the query used to generate it.

Alternatively, the Xapian::Database object has a get_termfreq() method
which will return the term frequency for any term in the database

The Xapian::MSet::get_termfreq() method can be faster (doesn't need to look
it up in the database, because it will already have been looked up when
performing the query), but will raise an exception if the term wasn't in
the query.

Omega uses the following to get the termfreq:

    try {
        value = int_to_string(mset.get_termfreq(args[0]));
    } catch (...) {
        value = int_to_string(db.get_termfreq(args[0]));
    }

(see line 1209 of query.cc in current SVN head).

-- 
Richard