Where can i get keyword database
 

bigger the better of a keyword database from search engines?

For free try to find on the SEO boards, for cash wordtracker.com

If you get an account at kanoodle you can coax them out of a adult terms list.

instead of getting the same ones everyone else does , you should try to find some unique sources for porn keywords ( if thats what your after ) . Like maybe hit up an adult search engine for their keywords list instead of the traditional ways

I have one with current 555.638 unique adult entries in all niches and in a mysql db and its growing for each day.

depending on what you want I can give you permanent access, hit me up and we can talk some prices.
icq: 58556083

btw, the list is uncensored and raw unlike overture etc. and will give real and better unique keywords. The only filter is cp related keywords which is removed so its also usefull for extreme searches.