diff --git a/db.go b/db.go
index d6a90a3..3175ecc 100644
--- a/db.go
+++ b/db.go
@@ -157,7 +157,7 @@ CREATE TABLE IF NOT EXISTS student_corrected(
 		return err
 	}
 	if _, err := db.Exec(`
-CREATE VIEW IF NOT EXISTS student_scores AS SELECT U.id_user, id_survey, Q.id_question, MAX(R.score) as score FROM survey_quests Q CROSS JOIN users U LEFT JOIN survey_responses R ON Q.id_question = R.id_question AND R.id_user = U.id_user GROUP BY Q.id_question, U.id_user;
+CREATE VIEW IF NOT EXISTS student_scores AS SELECT T.id_user, T.id_survey, Q.id_question, MAX(R.score) AS score FROM (SELECT DISTINCT R.id_user, S.id_survey FROM survey_responses R INNER JOIN survey_quests Q ON R.id_question = Q.id_question INNER JOIN surveys S ON Q.id_survey = S.id_survey) T LEFT OUTER JOIN survey_quests Q ON T.id_survey = Q.id_survey LEFT OUTER JOIN survey_responses R ON R.id_user = T.id_user AND Q.id_question = R.id_question GROUP BY id_user, id_survey, id_question;
 `); err != nil {
 		return err
 	}
diff --git a/surveys.go b/surveys.go
index 83f135a..872d971 100644
--- a/surveys.go
+++ b/surveys.go
@@ -12,6 +12,10 @@ import (
 	"github.com/julienschmidt/httprouter"
 )
 
+var (
+	_score_cache = map[int64]map[int64]*float64{}
+)
+
 func init() {
 	router.GET("/api/surveys", apiAuthHandler(
 		func(u *User, _ httprouter.Params, _ []byte) HTTPResponse {
@@ -182,9 +186,17 @@ func NewSurvey(title string, promo uint, group string, shown bool, startAvailabi
 }
 
 func (s Survey) GetScore(u *User) (score *float64, err error) {
-	err = DBQueryRow("SELECT SUM(score)/COUNT(*) FROM student_scores WHERE id_survey=? AND id_user=?", s.Id, u.Id).Scan(&score)
-	if score != nil {
-		*score = *score / 5.0
+	if _, ok := _score_cache[u.Id]; !ok {
+		_score_cache[u.Id] = map[int64]*float64{}
+	}
+	if v, ok := _score_cache[u.Id][s.Id]; ok {
+		score = v
+	} else {
+		err = DBQueryRow("SELECT SUM(score)/COUNT(*) FROM student_scores WHERE id_survey=? AND id_user=?", s.Id, u.Id).Scan(&score)
+		if score != nil {
+			*score = *score / 5.0
+		}
+		_score_cache[u.Id][s.Id] = score
 	}
 	return
 }