patch 4.0

unittest/sql/optimizer/test_optimizer_used_hint.sql

@@ -1,4 +1,5 @@
 ################################## Index Hint ##################################
+#测试主键index和普通index的情况
 select /*+FULL(t4)*/* from t4;
 select /*+INDEX(t4 idx_t4_c2_c3)*/* from t4;
 select /*+INDEX(t4 idx_t4_c2)*/* from t4;
@@ -7,33 +8,33 @@ select /*+INDEX(t_pt t_pt_idx_1)*/* from t_pt where (c2,c1) > (300,200);
 select /*+INDEX(t_pt primary)*/* from t_pt where (c2,c1) > (300,200);
 select /*+INDEX(t_pt primary)*/* from t_pt where (c1,c2) > (200,300);
 
-
+#测试无效index的情况
 select /*+INDEX(t4 idx_t4_invalid)*/* from t4;
 
-
+#测试同一个table 对应多个可选index
 select /*+INDEX(t4 idx_t4_c3) INDEX(t4 idx_t4_c2) INDEX(t4 idx_t4_c2_c3) */* from t4;
 select * from t4 use index(idx_t4_c3, idx_t4_c2, idx_t4_c2_c3);
 select * from t4 force index(idx_t4_c3, idx_t4_c2, idx_t4_c2_c3);
 select /*+INDEX(t4 idx_t4_c3) FULL(t4) */* from t4;
 
-
+#测试指定多个table index的情况
 select /*+INDEX(t4 idx_t4_c3) INDEX(t5 idx_t5_c2)*/* from t4,t5;
 
-
+#测试alias的情况
 select /*+INDEX(t4 idx_t4_c3)*/* from t4 as tt;
 select /*+INDEX(tt idx_t4_c3)*/* from t4 as tt;
 
-
+#测试index list为空的情况
 select * from t4 use index();
 
-
+#测试use_index与ignore_index混用的情况
 select /*+INDEX(t4 idx_t4_c3) */* from t4 ignore index(idx_t4_c3);
 
-
+##### 测试ingore的情况#####
 select * from t4 ignore index(idx_t4_c3);
 select * from t4 ignore index(idx_t4_c2);
 
-
+# 同时制定多个ingore, 当同时编写多个ingore时，只有第一个生效
 select * from t4 ignore index(idx_t4_c3, idx_t4_c2);
 select * from t4 ignore index(idx_t4_c3) ignore index(idx_t4_c2);
 
@@ -103,10 +104,10 @@ select /*+qb_name(select_1) qb_name(select_2)*/* from t4;
 select /*+qb_name(select_1) */* from t4 where t4.c1 > any(select /*+qb_name(select_2)*/c1 from t5);
 select /*+qb_name(select_1) */* from t4 where t4.c1 > any(select /*+qb_name(select_1)*/c1 from t5);
 
-################################## hint  ##################################
+################################## 测试不应该显示的hint  ##################################
 select /*+topk(1 100) hotspot max_concurrent(1)*/* from t4;
 
-################################## hint  #################################
+################################## 测试指定即生效的hint  #################################
 select /*+read_consistency("weak")*/* from t1;
 select /*+query_timeout(100)*/ * from t1;
 select /*+frozen_version(1)*/ * from t1;