Changes in /contrib/fulltextindex

Hi.

I have done some changes and improvements to the fulltextindex trigger
(contrib/fulltextindex). As these changes affects among other things the
parameter list I would like to ask the maintainer about his thoughts before
I submit a patch. And there comes the problem - there is no explizit
maintainer listed in the accompanying docs. The last changes according to
the cvs log has been done by Bruce Momjian.

Maybe the original author is subscribed to this list and can get in touch
with me because I'm kind of new to incorporation patches to a open source
project.

The changes made include:

+ Changed the split up behaviour from checking via isalpha to
using a list of delimiters as isalpha is a pain used with
data containing german umlauts, etc. ATM this list contains:

" ,;.:-_#/*+~^°!?\"\\§$%&()[]{}=<>|0123456789\n\r\t(at)µ"

+ If the do be indexed field has'nt changed, the indexing will
not be done. This way unnecessary redindexing of fields not
affected by an update can by omited.

+ There is a new field 'word' of type BOOL in the index table.
Using this field, it is possible to do 'full word' and
'substring' searches.

+ The text gets no longer lowercased before it is written into
the index table. This way it is possible to to casesensitive
and incasesenstive (via a functional index using lower) searches.

+ Added functionality to prevent indexing of duplicate words
(this is one item of the todo list in fti.c) using a hash
table. As this is chained to a significant loos of performance
and depends on the indexed data, this can be turned on or off
via a newly introduced parameter.

-Florian

--
"Computers are useless. They can only give you answers."
-- Pablo Picasso.