planner: check required order property for enforced stream aggregation (

pingcap#17338) (pingcap#17347)
sre-bot · May 22, 2020 · ffaae4f · ffaae4f
1 parent e0e32e1
commit ffaae4f
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Showing 4 changed files with 98 additions and 1 deletion.
diff --git a/planner/core/exhaust_physical_plans.go b/planner/core/exhaust_physical_plans.go
@@ -1599,7 +1599,9 @@ func (la *LogicalAggregation) getEnforcedStreamAggs(prop *property.PhysicalPrope
 		Enforced:    true,
 		Items:       property.ItemsFromCols(la.groupByCols, desc),
 	}
-
+	if !prop.IsPrefix(childProp) {
+		return enforcedAggs
+	}
 	taskTypes := []property.TaskType{property.CopSingleReadTaskType, property.CopDoubleReadTaskType}
 	if la.HasDistinct() {
 		// TODO: remove AllowDistinctAggPushDown after the cost estimation of distinct pushdown is implemented.

diff --git a/planner/core/integration_test.go b/planner/core/integration_test.go
@@ -952,3 +952,29 @@ func (s *testIntegrationSerialSuite) TestIssue16837(c *C) {
 	tk.MustExec("insert into t values (2, 1, 1, 1, 2)")
 	tk.MustQuery("select /*+ use_index_merge(t,c,idx_ab) */ * from t where a = 1 or (e = 1 and c = 1)").Check(testkit.Rows())
 }
+
+func (s *testIntegrationSuite) TestStreamAggProp(c *C) {
+	tk := testkit.NewTestKit(c, s.store)
+
+	tk.MustExec("use test")
+	tk.MustExec("drop table if exists t")
+	tk.MustExec("create table t(a int)")
+	tk.MustExec("insert into t values(1),(1),(2)")
+
+	var input []string
+	var output []struct {
+		SQL  string
+		Plan []string
+		Res  []string
+	}
+	s.testData.GetTestCases(c, &input, &output)
+	for i, tt := range input {
+		s.testData.OnRecord(func() {
+			output[i].SQL = tt
+			output[i].Plan = s.testData.ConvertRowsToStrings(tk.MustQuery("explain " + tt).Rows())
+			output[i].Res = s.testData.ConvertRowsToStrings(tk.MustQuery(tt).Rows())
+		})
+		tk.MustQuery("explain " + tt).Check(testkit.Rows(output[i].Plan...))
+		tk.MustQuery(tt).Check(testkit.Rows(output[i].Res...))
+	}
+}
diff --git a/planner/core/testdata/integration_suite_in.json b/planner/core/testdata/integration_suite_in.json
@@ -127,5 +127,14 @@
       "explain select * from t where a in (14, floor(3.47))",
       "explain select * from t where b in (3, 4)"
     ]
+  },
+  {
+    "name": "TestStreamAggProp",
+    "cases": [
+      "select /*+ stream_agg() */ count(*) c from t group by a order by c limit 1",
+      "select /*+ stream_agg() */ count(*) c from t group by a order by c",
+      "select /*+ stream_agg() */ count(*) c from t group by a order by a limit 1",
+      "select /*+ stream_agg() */ count(*) c from t group by a order by a"
+    ]
   }
 ]
diff --git a/planner/core/testdata/integration_suite_out.json b/planner/core/testdata/integration_suite_out.json
@@ -582,5 +582,65 @@
         ]
       }
     ]
+  },
+  {
+    "Name": "TestStreamAggProp",
+    "Cases": [
+      {
+        "SQL": "select /*+ stream_agg() */ count(*) c from t group by a order by c limit 1",
+        "Plan": [
+          "TopN_10 1.00 root  Column#3:asc, offset:0, count:1",
+          "└─StreamAgg_17 8000.00 root  group by:test.t.a, funcs:count(1)->Column#3",
+          "  └─Sort_22 10000.00 root  test.t.a:asc",
+          "    └─TableReader_21 10000.00 root  data:TableFullScan_20",
+          "      └─TableFullScan_20 10000.00 cop[tikv] table:t keep order:false, stats:pseudo"
+        ],
+        "Res": [
+          "1"
+        ]
+      },
+      {
+        "SQL": "select /*+ stream_agg() */ count(*) c from t group by a order by c",
+        "Plan": [
+          "Sort_5 8000.00 root  Column#3:asc",
+          "└─StreamAgg_11 8000.00 root  group by:test.t.a, funcs:count(1)->Column#3",
+          "  └─Sort_16 10000.00 root  test.t.a:asc",
+          "    └─TableReader_15 10000.00 root  data:TableFullScan_14",
+          "      └─TableFullScan_14 10000.00 cop[tikv] table:t keep order:false, stats:pseudo"
+        ],
+        "Res": [
+          "1",
+          "2"
+        ]
+      },
+      {
+        "SQL": "select /*+ stream_agg() */ count(*) c from t group by a order by a limit 1",
+        "Plan": [
+          "Projection_8 1.00 root  Column#3",
+          "└─Limit_14 1.00 root  offset:0, count:1",
+          "  └─StreamAgg_27 1.00 root  group by:test.t.a, funcs:count(1)->Column#3, funcs:firstrow(test.t.a)->test.t.a",
+          "    └─Sort_32 1.25 root  test.t.a:asc",
+          "      └─TableReader_31 1.25 root  data:TableFullScan_30",
+          "        └─TableFullScan_30 1.25 cop[tikv] table:t keep order:false, stats:pseudo"
+        ],
+        "Res": [
+          "2"
+        ]
+      },
+      {
+        "SQL": "select /*+ stream_agg() */ count(*) c from t group by a order by a",
+        "Plan": [
+          "Projection_6 8000.00 root  Column#3",
+          "└─StreamAgg_21 8000.00 root  group by:test.t.a, funcs:count(1)->Column#3, funcs:firstrow(test.t.a)->test.t.a",
+          "  └─Sort_17 10000.00 root  test.t.a:asc",
+          "    └─TableReader_16 10000.00 root  data:TableFullScan_15",
+          "      └─TableFullScan_15 10000.00 cop[tikv] table:t keep order:false, stats:pseudo"
+        ],
+        "Res": [
+          "2",
+          "1"
+        ]
+      }
+    ]
   }
 ]