Ferret talk - Dec 2006 - Effective search when knowing ID

Hi list,

I''m new to ferret and I wonder what is the best way to search if I  
know one fields id and want to search on its content.
I have experimented with FilteredQuery but I don''t know if this is  
the best way.
Eg.

index = Index::Index.new(:path => ''/tmp/all'')
@dbh = Database.instance.connect
result = @dbh.exec("SELECT pk_fulltext_id, fulltext_text FROM  
tbl_fulltext")
result.each do |row|
	#Inserting the PK id and text from DB
	index << {:pk_fulltext_id => row[''pk_fulltext_id''],
:content => row
[''fulltext_text'']}
end

content_query = Search::WildcardQuery.new(:content, "Text*")

# I know the ID of the text to search in so I want to do it efficient
id_filter = Search::QueryFilter.new(Search::TermQuery.new 
(''pk_fulltext_id'', ''1257667''))

query = Search::FilteredQuery.new(content_query, id_filter)

index.search_each(query) do |id, score|
     puts "Document #{id} found with a score of #{score}"
    highlights = index.highlight(content_query, id,
                                     :field => :content,
                                     :pre_tag => "\033[36m",
                                     :post_tag => "\033[m",
           			 :excerpt_length => 100)
   puts highlights
end

Please comment of this!
Can I make my database PK id to be the ferret document ID??
Would that speed it up?

Cheers,
Henrik

On Fri, Dec 01, 2006 at 02:52:31PM +0100, Henrik Zagerholm
wrote:
> Hi list,
> 
> I''m new to ferret and I wonder what is the best way to search if I
> know one fields id and want to search on its content.
> I have experimented with FilteredQuery but I don''t know if this is
> the best way.
interesting question, but I''m afraid I can''t give a definite
answer.

I''d guess that all you can do is try out what is faster - the query
filter or an added boolean clause in your query. 

In general I wouldn''t expect any speed difference in a query matching a
single document issued with or without an additional clause matching the 
id field of that document. 

There will be some speed improvement if your query matches more
documents, but mainly because you narrow the result set that Ferret has
to return to down to one element, not because search is faster.

Jens

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