What's the diff between glimpse -i -l -z and -N -y -z?

[Bryan Thale <thale@rsch.comm.mot.com>]

What exactly is the difference between using glimpse options -i -l -z
vs. -N -y -z?

I know -N searches only the index whereas -i -l searches the index and
the files, but why do they return different result sets?  The -N option
returns many more "matches" but many of the matches are false.  I'm
getting matches returned for files that don't match my queries even
remotely.  For example searching for 'compression;algorithm' returns
files that don't contain either word in any form.

>From what I've been able to understand from the docs, I would expect
both sets of options to return the same list of files in this case,
namely all files that contain matches for '*compression*' and
'*algorithm*' anywhere in the file.  Obviously, I'm missing some crucial
point since that isn't what glimpse is giving me.  What am I missing and
why is the -N option returning files that don't match the query?

I'm using glimpse 4.12.6 on RH Linux 6.1 if that makes any difference.

Thanks,
Bryan.

--
Bryan Thale
Motorola Labs, Networking and Infrastructure Research
mailto:thale@rsch.comm.mot.com