Ejemplo n.º 1
0
// The return type of a CASE expression is the compatible aggregated type of all return values,
// but also depends on the context in which it is used.
// If used in a string context, the result is returned as a string.
// If used in a numeric context, the result is returned as a decimal, real, or integer value.
func (v *typeInferrer) handleCaseExpr(x *ast.CaseExpr) {
	var currType *types.FieldType
	for _, w := range x.WhenClauses {
		t := w.Result.GetType()
		if currType == nil {
			currType = t
			continue
		}
		mtp := types.MergeFieldType(currType.Tp, t.Tp)
		if mtp == t.Tp && mtp != currType.Tp {
			currType.Charset = t.Charset
			currType.Collate = t.Collate
		}
		currType.Tp = mtp

	}
	if x.ElseClause != nil {
		t := x.ElseClause.GetType()
		if currType == nil {
			currType = t
		} else {
			mtp := types.MergeFieldType(currType.Tp, t.Tp)
			if mtp == t.Tp && mtp != currType.Tp {
				currType.Charset = t.Charset
				currType.Collate = t.Collate
			}
			currType.Tp = mtp
		}
	}
	x.SetType(currType)
	// TODO: We need a better way to set charset/collation
	x.Type.Charset, x.Type.Collate = types.DefaultCharsetForType(x.Type.Tp)
}
Ejemplo n.º 2
0
func (b *executorBuilder) buildSemiJoin(v *plan.PhysicalHashSemiJoin) Executor {
	var leftHashKey, rightHashKey []*expression.Column
	var targetTypes []*types.FieldType
	for _, eqCond := range v.EqualConditions {
		ln, _ := eqCond.Args[0].(*expression.Column)
		rn, _ := eqCond.Args[1].(*expression.Column)
		leftHashKey = append(leftHashKey, ln)
		rightHashKey = append(rightHashKey, rn)
		targetTypes = append(targetTypes, types.NewFieldType(types.MergeFieldType(ln.GetType().Tp, rn.GetType().Tp)))
	}
	e := &HashSemiJoinExec{
		schema:       v.GetSchema(),
		otherFilter:  expression.ComposeCNFCondition(v.OtherConditions),
		bigFilter:    expression.ComposeCNFCondition(v.LeftConditions),
		smallFilter:  expression.ComposeCNFCondition(v.RightConditions),
		bigExec:      b.build(v.GetChildByIndex(0)),
		smallExec:    b.build(v.GetChildByIndex(1)),
		prepared:     false,
		ctx:          b.ctx,
		bigHashKey:   leftHashKey,
		smallHashKey: rightHashKey,
		withAux:      v.WithAux,
		anti:         v.Anti,
		targetTypes:  targetTypes,
	}
	return e
}
Ejemplo n.º 3
0
func (b *executorBuilder) buildJoin(v *plan.PhysicalHashJoin) Executor {
	var leftHashKey, rightHashKey []*expression.Column
	var targetTypes []*types.FieldType
	for _, eqCond := range v.EqualConditions {
		ln, _ := eqCond.Args[0].(*expression.Column)
		rn, _ := eqCond.Args[1].(*expression.Column)
		leftHashKey = append(leftHashKey, ln)
		rightHashKey = append(rightHashKey, rn)
		targetTypes = append(targetTypes, types.NewFieldType(types.MergeFieldType(ln.GetType().Tp, rn.GetType().Tp)))
	}
	e := &HashJoinExec{
		schema:        v.GetSchema(),
		otherFilter:   expression.ComposeCNFCondition(v.OtherConditions),
		prepared:      false,
		ctx:           b.ctx,
		targetTypes:   targetTypes,
		concurrency:   v.Concurrency,
		defaultValues: v.DefaultValues,
	}
	if v.SmallTable == 1 {
		e.smallFilter = expression.ComposeCNFCondition(v.RightConditions)
		e.bigFilter = expression.ComposeCNFCondition(v.LeftConditions)
		e.smallHashKey = rightHashKey
		e.bigHashKey = leftHashKey
		e.leftSmall = false
	} else {
		e.leftSmall = true
		e.smallFilter = expression.ComposeCNFCondition(v.LeftConditions)
		e.bigFilter = expression.ComposeCNFCondition(v.RightConditions)
		e.smallHashKey = leftHashKey
		e.bigHashKey = rightHashKey
	}
	if v.JoinType == plan.LeftOuterJoin || v.JoinType == plan.RightOuterJoin {
		e.outer = true
	}
	if e.leftSmall {
		e.smallExec = b.build(v.GetChildByIndex(0))
		e.bigExec = b.build(v.GetChildByIndex(1))
	} else {
		e.smallExec = b.build(v.GetChildByIndex(1))
		e.bigExec = b.build(v.GetChildByIndex(0))
	}
	for i := 0; i < e.concurrency; i++ {
		ctx := &hashJoinCtx{}
		if e.bigFilter != nil {
			ctx.bigFilter = e.bigFilter.Clone()
		}
		if e.otherFilter != nil {
			ctx.otherFilter = e.otherFilter.Clone()
		}
		ctx.datumBuffer = make([]types.Datum, len(e.bigHashKey))
		ctx.hashKeyBuffer = make([]byte, 0, 10000)
		e.hashJoinContexts = append(e.hashJoinContexts, ctx)
	}
	return e
}
Ejemplo n.º 4
0
//TODO: select join algorithm during cbo phase.
func (b *executorBuilder) buildJoin(v *plan.PhysicalHashJoin) Executor {
	var leftHashKey, rightHashKey []*expression.Column
	var targetTypes []*types.FieldType
	for _, eqCond := range v.EqualConditions {
		ln, _ := eqCond.Args[0].(*expression.Column)
		rn, _ := eqCond.Args[1].(*expression.Column)
		leftHashKey = append(leftHashKey, ln)
		rightHashKey = append(rightHashKey, rn)
		targetTypes = append(targetTypes, types.NewFieldType(types.MergeFieldType(ln.GetType().Tp, rn.GetType().Tp)))
	}
	e := &HashJoinExec{
		schema:      v.GetSchema(),
		otherFilter: expression.ComposeCNFCondition(v.OtherConditions),
		prepared:    false,
		ctx:         b.ctx,
		targetTypes: targetTypes,
	}
	if v.SmallTable == 1 {
		e.smallFilter = expression.ComposeCNFCondition(v.RightConditions)
		e.bigFilter = expression.ComposeCNFCondition(v.LeftConditions)
		e.smallHashKey = rightHashKey
		e.bigHashKey = leftHashKey
		e.leftSmall = false
	} else {
		e.leftSmall = true
		e.smallFilter = expression.ComposeCNFCondition(v.LeftConditions)
		e.bigFilter = expression.ComposeCNFCondition(v.RightConditions)
		e.smallHashKey = leftHashKey
		e.bigHashKey = rightHashKey
	}
	if v.JoinType == plan.LeftOuterJoin || v.JoinType == plan.RightOuterJoin {
		e.outer = true
	}
	if e.leftSmall {
		e.smallExec = b.build(v.GetChildByIndex(0))
		e.bigExec = b.build(v.GetChildByIndex(1))
	} else {
		e.smallExec = b.build(v.GetChildByIndex(1))
		e.bigExec = b.build(v.GetChildByIndex(0))
	}
	return e
}