Performance

["Bert" <clemens.bertschler@xxxxxxxxx>]

Hi List
I have maybe an easy question but i do not find an answer, i have this
SQL query:

SELECT geom,group,production_facs FROM south_america
               WHERE municipio = ''
                       OR municipio = 'ACRE'
                       OR municipio = 'ADJUNTAS'
                       OR municipio = 'AGUADA'

The performance of this query is quite worse as longer it gets, its
possible that this query gets over 20 to 30 OR comparisons, but then
the performance is really worse, is it possible to speed it up?
Thanks
Clemens