Table: race_results_9
Columns: year
entrant
chassis
engine
points

Question: Which engine did dr ing f porsche kg use with the porsche rsk (f2) chassis?
SQL: SELECT "engine" FROM race_results_9 WHERE "entrant" = 'dr ing f porsche kg' AND "chassis" = 'porsche rsk (f2)'

Question: What chassis did the porsche flat-4 use before 1958?
SQL: SELECT "chassis" FROM race_results_9 WHERE "engine" = 'porsche flat-4' AND "year" < 1958

Question: What engine did the porsche 718 chassis use?
SQL: SELECT "engine" FROM race_results_9 WHERE "chassis" = 'porsche 718'

Question: Which year had more than 0 points?
SQL: SELECT COUNT("year") FROM race_results_9 WHERE "points" > 0