case and accent insensitive

[MOISES ESPINOSA <moikmeg@xxxxxxxxx>]

Hi,

I need to reproduced the following Oracle functionality in PostgreSQL:

CREATE INDEX index_ciudad ON world.ciudad ((NLSSORT(NOMBRE29,'nls_sort=''GENERIC_BASELETTER''')));

I don't know how i could reproduced case insensitive and accent insensitive.

Is there any collate?

Thanks.