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From Jenny Brown <skyw...@gmail.com>
Subject Re: operator precedence and confusing result
Date Thu, 12 Mar 2009 02:13:07 GMT
I use the boolean logic heavily in a production app, because it's the
grammar that my users understand (and they put together complex
boolean queries in other apps too).  Also, we're not using relevance
ranking.  A document either "matches the query" and gets returned, or
"doesn't match" and doesn't get returned.  We only want yes/no
answers.

I haven't had time to really figure out what the earlier commenter
meant with the + operators syntax conversion.  I still thought it
would have meant the same thing as the query I had posted, ie, article
has to match all terms in the AND clauses, and at least one of the
terms in the OR list.  I guess I'm still missing what his explanation
was trying to demonstrate.

Anyway, just a note to say that boolean matching is important to me
and my users; it'd be good if it worked the way it looks like it
would.  If it doesn't, I need to understand better what the current
limitations are.

I'll be out of town and away from net for 4 days, starting tomorrow,
so I'll have to continue conversation once I'm back.  Thanks for the
help and comments thus far.

Jenny Brown


On Wed, Mar 11, 2009 at 8:58 PM, Mike Klaas <mike.klaas@gmail.com> wrote:
>
> On 8-Mar-09, at 3:46 PM, Chris Hostetter wrote:
>>
>> it's important to rememebr that Lucene isn't a boolean matching system --
>> the undelrying semantics are MUST/MUST_NOT/SHOULD -- the AND/OR
>> keywords are just syntactic sugar that attempt to apply underlying
>> semantics as binary opperators.
>
> Has anyone (but me) considered ripping out this misleading (and imho not
> terribly useful) syntactic sugar in Lucene 3.0?  It seems that the boolean
> operator support is little but an impediment to understanding the Lucene
> query model.  Analogies that only occasionally accord with a person's
> intuition are among the most dangerous.
>
> There could always be a query parser mode or module that is devoted to
> parsing boolean operators correctly.
>
> -Mike
>

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