In general, the type of feature you are interested in is typcially caleld
a "PrefixQuery" you can acomplish it with the SolrQueryParser using "a*"
http://wiki.apache.org/solr/SolrQuerySyntax
: example show all docs starting with an "a" or "A", I would just add an
: extra field only containing the first letter. This is *much* faster in
the EdgeNGramTokenizerFactory should actaully make this
trivial for you ... you can copyField the value into an "initial" field
and let the Tokenizer do all the work of indexing only teh first
character.
: lucene, and for many documents you don't risk the too many boolean
: clauses (though you can set it very high, at the cost of memory)
this isn't actually a problem in Solr .. the SolrQueryParser doesn't use
regualr PrefixQueries, it rewritesthem into PrefixFilter's which don't hit
the boolean clauses limit.
-Hoss
