Does somebodoy know query language DataLog ? Where I'm able to find something about this ?I can'h find any tutorial on internet :/

Datalog is basically a subset of Prolog without any composite predicates and a few other vices on the sorts of negations and rule arrangements that you can do.

See:

http://en.wikipedia.org/wiki/Datalog

perhaps you have attempted google? first entry for "datalog tutorial": http://www.ccs.neu.edu/home/ramsdell/tools/datalog/datalog.html