Query results caching?

Hi all,

I dont know how its called but I noticed that when I query the db for
the first time it give me the result slower then the next times ill
repeat the same exact query, I figure that its some kind of caching so
henceforth the title of the mail :)

Anyway I would want to be able to delete that "caching" after every
query test that I run, cause I want to see the real time results for my
queries (its for a searching option for users so it will vary alot).

Is it possible to do it manually each time or maybe only from the
configuration?

Thanks in advance,
Ben-Nes Yonatan
Canaan Surfing ltd.
http://www.canaan.net.il