[Koha] Problems with slow search in OPAC solved, remains one question

[Camilo Freire]

Following the suggestions by Jonathan Druart, Mark Tompsett and Barton
Chittenden the problem is solved by disabling the zebra_facets option in
the koha-conf.xml file.

The next question is about what Barton Chittenden says: when some words
like articles or prepositons and included in the query string, in one hand
the search is slower and on the other hand the amount of "noise"* in the
response is great. In fact the most problematics searches where those in
which the spanish word "de" (of) appeared.

What could be the solution for this problema? Disable the Fuzzy and
Stemming search? I read that there is no stopwords list in Koha today.
Could I write a function for "cleaning" the query string before the seach
is made?

Thanks in advance.
Saludos
Camilo

*I dont know if its the suitable english word...