datatype for indexable char field larger than 256

i'm parsing DMOZ data files, and i need to store the path and later
reference it to get the associated CatID to store for the parent of the
child paths. however, some of the paths are larger than 500 chars. would a
WHERE clause like this:

   ... WHERE path='top/this/really/long/500/char/path'

work if i define the field 'path' as type text? also, type text field
aren't indexable or are they?

suggestions are welcomed. thanks in advance.