planner: make hint read_from_storage take effect for tikv (pingcap#…

…13578)
lzmhhh123 · Jan 19, 2020 · 12a9adf · 12a9adf
1 parent 67b66c7
commit 12a9adf
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Showing 3 changed files with 29 additions and 5 deletions.
diff --git a/planner/core/cbo_test.go b/planner/core/cbo_test.go
@@ -1080,6 +1080,10 @@ func (s *testAnalyzeSuite) TestTiFlashCostModel(c *C) {
 		"TableReader_7 10000.00 root data:TableScan_6",
 		"└─TableScan_6 10000.00 cop[tiflash] table:t, range:[-inf,+inf], keep order:false, stats:pseudo",
 	))
+	tk.MustQuery("desc select /*+ read_from_storage(tikv[t]) */ * from t").Check(testkit.Rows(
+		"TableReader_5 10000.00 root data:TableScan_4",
+		"└─TableScan_4 10000.00 cop[tikv] table:t, range:[-inf,+inf], keep order:false, stats:pseudo",
+	))
 	tk.MustQuery("desc select * from t where t.a = 1 or t.a = 2").Check(testkit.Rows(
 		"TableReader_6 2.00 root data:TableScan_5",
 		"└─TableScan_5 2.00 cop[tikv] table:t, range:[1,1], [2,2], keep order:false, stats:pseudo",

diff --git a/planner/core/logical_plan_builder.go b/planner/core/logical_plan_builder.go
@@ -399,6 +399,16 @@ func (ds *DataSource) setPreferredStoreType(hintInfo *tableHintInfo) {
 	if hintInfo.ifPreferTiFlash(alias) {
 		ds.preferStoreType |= preferTiFlash
 	}
+	if hintInfo.ifPreferTiKV(alias) {
+		if ds.preferStoreType != 0 {
+			errMsg := fmt.Sprintf("Storage hints are conflict, you can only specify one storage type of table %s", alias.L)
+			warning := ErrInternal.GenWithStack(errMsg)
+			ds.ctx.GetSessionVars().StmtCtx.AppendWarning(warning)
+			ds.preferStoreType = 0
+			return
+		}
+		ds.preferStoreType |= preferTiKV
+	}
 }
 
 func resetNotNullFlag(schema *expression.Schema, start, end int) {
@@ -1991,7 +2001,7 @@ func (b *PlanBuilder) pushTableHints(hints []*ast.TableOptimizerHint, nodeType n
 	var (
 		sortMergeTables, INLJTables, hashJoinTables []hintTableInfo
 		indexHintList                               []indexHintInfo
-		tiflashTables                               []hintTableInfo
+		tiflashTables, tikvTables                   []hintTableInfo
 		aggHints                                    aggHintInfo
 	)
 	for _, hint := range hints {
@@ -2034,18 +2044,23 @@ func (b *PlanBuilder) pushTableHints(hints []*ast.TableOptimizerHint, nodeType n
 			if hint.StoreType.L == HintTiFlash {
 				tiflashTables = tableNames2HintTableInfo(hint.Tables)
 			}
+			if hint.StoreType.L == HintTiKV {
+				tikvTables = tableNames2HintTableInfo(hint.Tables)
+			}
 		default:
 			// ignore hints that not implemented
 		}
 	}
-	if len(sortMergeTables)+len(INLJTables)+len(hashJoinTables)+len(indexHintList)+len(tiflashTables) > 0 || aggHints.preferAggType != 0 || aggHints.preferAggToCop {
+	if len(sortMergeTables)+len(INLJTables)+len(hashJoinTables)+len(indexHintList)+len(tiflashTables)+len(tikvTables) > 0 ||
+		aggHints.preferAggType != 0 || aggHints.preferAggToCop {
 		b.tableHintInfo = append(b.tableHintInfo, tableHintInfo{
 			sortMergeJoinTables:       sortMergeTables,
 			indexNestedLoopJoinTables: INLJTables,
 			hashJoinTables:            hashJoinTables,
 			indexHintList:             indexHintList,
 			aggHints:                  aggHints,
-			flashTables:               tiflashTables,
+			tiflashTables:               tiflashTables,
+			tikvTables:                tikvTables,
 		})
 		return true
 	}

diff --git a/planner/core/planbuilder.go b/planner/core/planbuilder.go
@@ -60,7 +60,8 @@ type tableHintInfo struct {
 	sortMergeJoinTables       []hintTableInfo
 	hashJoinTables            []hintTableInfo
 	indexHintList             []indexHintInfo
-	flashTables               []hintTableInfo
+	tiflashTables       	  []hintTableInfo
+	tikvTables          	  []hintTableInfo
 	aggHints                  aggHintInfo
 }
 
@@ -103,7 +104,11 @@ func (info *tableHintInfo) ifPreferINLJ(tableNames ...*model.CIStr) bool {
 }
 
 func (info *tableHintInfo) ifPreferTiFlash(tableNames ...*model.CIStr) bool {
-	return info.matchTableName(tableNames, info.flashTables)
+	return info.matchTableName(tableNames, info.tiflashTables)
+}
+
+func (info *tableHintInfo) ifPreferTiKV(tableNames ...*model.CIStr) bool {
+	return info.matchTableName(tableNames, info.tikvTables)
 }
 
 // matchTableName checks whether the hint hit the need.