enable vectorized expression evaluation by default

pingcap · Sep 1, 2019 · 9513127 · 9513127
1 parent bbb70be
commit 9513127
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Showing 5 changed files with 23 additions and 11 deletions.
diff --git a/executor/projection.go b/executor/projection.go
@@ -172,6 +172,9 @@ func (e *ProjectionExec) unParallelExecute(ctx context.Context, chk *chunk.Chunk
 	if err != nil {
 		return err
 	}
+	if e.childResult.NumRows() == 0 {
+		return nil
+	}
 	err = e.evaluatorSuit.Run(e.ctx, e.childResult, chk)
 	return err
 }

diff --git a/expression/chunk_executor.go b/expression/chunk_executor.go
@@ -95,8 +95,10 @@ func evalOneVec(ctx sessionctx.Context, expr Expression, input *chunk.Chunk, out
 		}
 		if ft.Tp == mysql.TypeFloat {
 			f64s := result.Float64s()
-			buf := chunk.NewColumn(ft, input.NumRows())
-			buf.ResizeFloat32(input.NumRows())
+			n := input.NumRows()
+			buf := chunk.NewColumn(ft, n)
+			buf.ResizeFloat32(n)
+			buf.SetNulls(0, n, false)
 			f32s := buf.Float32s()
 			for i := range f64s {
 				if result.IsNull(i) {

diff --git a/expression/constant.go b/expression/constant.go
@@ -162,7 +162,7 @@ func (c *Constant) VecEvalTime(ctx sessionctx.Context, input *chunk.Chunk, resul
 // VecEvalDuration evaluates this expression in a vectorized manner.
 func (c *Constant) VecEvalDuration(ctx sessionctx.Context, input *chunk.Chunk, result *chunk.Column) error {
 	if c.DeferredExpr == nil {
-		return genVecFromConstExpr(ctx, c, types.ETDecimal, input, result)
+		return genVecFromConstExpr(ctx, c, types.ETDuration, input, result)
 	}
 	return c.DeferredExpr.VecEvalDuration(ctx, input, result)
 }
@@ -443,5 +443,8 @@ func (c *Constant) resolveIndices(_ *Schema) error {
 
 // Vectorized returns if this expression supports vectorized evaluation.
 func (c *Constant) Vectorized() bool {
+	if c.DeferredExpr != nil {
+		return c.DeferredExpr.Vectorized()
+	}
 	return true
 }
diff --git a/expression/vectorized.go b/expression/vectorized.go
@@ -25,6 +25,10 @@ func genVecFromConstExpr(ctx sessionctx.Context, expr Expression, targetType typ
 	if input != nil {
 		n = input.NumRows()
 	}
+	if n == 0 {
+		result.Reset()
+		return nil
+	}
 	switch targetType {
 	case types.ETInt:
 		result.ResizeInt64(n)
@@ -93,13 +97,13 @@ func genVecFromConstExpr(ctx sessionctx.Context, expr Expression, targetType typ
 			return err
 		}
 		if isNull {
-			for i := 0; i < n; i++ {
-				result.AppendNull()
-			}
-		} else {
-			for i := 0; i < n; i++ {
-				result.AppendDuration(v)
-			}
+			result.SetNulls(0, n, true)
+			return nil
+		}
+		result.SetNulls(0, n, false)
+		ds := result.GoDurations()
+		for i := range ds {
+			ds[i] = v.Duration
 		}
 	case types.ETJson:
 		result.ReserveJSON(n)

diff --git a/sessionctx/variable/tidb_vars.go b/sessionctx/variable/tidb_vars.go
@@ -347,7 +347,7 @@ const (
 	DefTiDBForcePriority               = mysql.NoPriority
 	DefTiDBUseRadixJoin                = false
 	DefEnableWindowFunction            = true
-	DefEnableVectorizedExpression      = false
+	DefEnableVectorizedExpression      = true
 	DefTiDBOptJoinReorderThreshold     = 0
 	DefTiDBDDLSlowOprThreshold         = 300
 	DefTiDBUseFastAnalyze              = false