Re: Support for boolean queries in apropos

[David Young <dyoung%pobox.com@localhost>]

On Sun, Mar 11, 2012 at 02:56:48PM +0530, Abhinav Upadhyay wrote:
> Hi all,
> 
> The FTS engine of Sqlite supports Boolean queries. Boolean queries
> simply means building complex queries by combining simple queries
> using Boolean operators: AND, OR, and NOT. For example:
> 
> $ apropos add new user NOT (git OR ssh)
> 
> This will provide results which match the query "add new user" but do
> not match for "git" or "ssh".
> 
> It is possible to combine such queries using parenthesis. It is a
> powerful and useful feature but till now apropos was unable to use it,
> the reason being that, it was removing away the keywords AND, OR, NOT
> as stopwords. I think there are two ways to handle this:

I think that general boolean queries are known now to be less powerful
and useful than everyone supposed that they were 20 or 30 years ago, so
search engines either omit support for boolean operators or else do not
encourage the use of such operators.  Instead, usually you can specify
terms that MUST appear in the results, and terms that MUST NOT appear,
using either a simplified set of operators (+ and -) or an "Advanced"
search form that has fields for the MUST/MUST-NOT terms.  Is there any
reason to believe that boolean operators are more suitable for apropos
than for other search engines?

ISTR you wrote the other day that terms are not weighted and the search
results are not ranked?  It seems to me that correcting that may improve
the effectiveness of apropos more than any other measure.

Dave

-- 
David Young
dyoung%pobox.com@localhost    Urbana, IL    (217) 721-9981