Postgres modulus operator on strings

Question

I run this query on Postgres 9.4 and I don't know why it returns true

SELECT 'Sao Paulo' % 'sao paulu'

Last character is different. Maybe its connected with full text search somehow? Or maybe some type casting is going in the background?

Any suggestions on modulo with strings?

Answer 1

I've found the answer:

http://www.postgresql.org/docs/9.1/static/pgtrgm.html

text % text boolean Returns true if its arguments have a similarity that is greater than the current similarity threshold set by set_limit.