Ya just gotta stop thinking like a database guy, man <G>. Lucene searches
lots and lots of text very well. It doesn't do joins worth a darn. The
moment
you star thinking in terms of sub-queries, you're probably starting down the
wrong track.
Here's a possibility. Index each post and all associated comments as a
single
document, with the post and all comments put in the same field. Something
like
doc.add("text", <original post text>);
doc.add("text", <first comment>);
doc.add("text", <second comment>);
add the document to the index.....
Now, all you need to do is search the "text" field and you get everything.
If
you set the position increment gap to something other than 1 (see the docs),
you can distinguish between the individual calls to doc.add(), see
getPositionIncrementGap.
In general, when indexing anything database-related, the advice is to
flatten
then data as you put it into a Lucene index. Think about making all the data
available as the result of a single query. This leads to data replication,
which
goes against all your database instincts, but....
HTH
Erick
On Wed, Dec 23, 2009 at 8:35 AM, Shahid Faiz <developer.in...@gmail.com>wrote:
> Hi,
>
> Following are details of my problem and possible solutions which I can
> think
> of. Please suggest which should I choose, or is there any other approach
> better than these.
>
> I want to index blog posts and their comments, in my database posts and
> comments are stored in two different tables. Currently I am indexing posts
> only and search works perfectly fine, but now I want to index comments as
> well. From now on when user will search any word, all posts will be
> displayed which meet search criteria including posts and only those
> comments
> which meet the specified criteria along with posts. All paging is done on
> posts, comments are not considered while calculating page contents.
>
> e.g.
>
> POST => Google launched Chrome Browser
> COMMENT => Microsoft IE also has tab browsing.
>
> Now searching (microsoft AND IE), should also display this post with along
> with above comment.
>
> One solution is: I should index both posts+comments in one lucene index and
> search that index. But as i have to display 10 posts (not including
> comments) per page so it gets complicated while finding records to be
> displayed on any given page. I think, I can solve this problem by creating
> two queries one to search posts and one to search comments only and then
> can
> join them using OR operator.
>
> Second solution could be: I can store comments in different index, and on
> search first I will execute query on comments index and use result of
> comments search to search blog posts.
>
> Thanks in advance.
>
> - deve
>
