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							90 lines
						
					
					
						
							3.2 KiB
						
					
					
				
			
		
		
	
	
							90 lines
						
					
					
						
							3.2 KiB
						
					
					
				| // Copyright 2015 PingCAP, Inc.
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| //
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| // Licensed under the Apache License, Version 2.0 (the "License");
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| // you may not use this file except in compliance with the License.
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| // You may obtain a copy of the License at
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| //
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| //     http://www.apache.org/licenses/LICENSE-2.0
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| //
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| // Unless required by applicable law or agreed to in writing, software
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| // distributed under the License is distributed on an "AS IS" BASIS,
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| // See the License for the specific language governing permissions and
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| // limitations under the License.
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| 
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| package optimizer
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| 
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| import (
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| 	"github.com/juju/errors"
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| 	"github.com/pingcap/tidb/ast"
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| 	"github.com/pingcap/tidb/context"
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| 	"github.com/pingcap/tidb/infoschema"
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| 	"github.com/pingcap/tidb/mysql"
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| 	"github.com/pingcap/tidb/optimizer/plan"
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| 	"github.com/pingcap/tidb/terror"
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| )
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| 
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| // Optimize does optimization and creates a Plan.
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| // The node must be prepared first.
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| func Optimize(ctx context.Context, node ast.Node, sb plan.SubQueryBuilder) (plan.Plan, error) {
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| 	// We have to infer type again because after parameter is set, the expression type may change.
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| 	if err := InferType(node); err != nil {
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| 		return nil, errors.Trace(err)
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| 	}
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| 	if err := logicOptimize(ctx, node); err != nil {
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| 		return nil, errors.Trace(err)
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| 	}
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| 	p, err := plan.BuildPlan(node, sb)
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| 	if err != nil {
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| 		return nil, errors.Trace(err)
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| 	}
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| 	err = plan.Refine(p)
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| 	if err != nil {
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| 		return nil, errors.Trace(err)
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| 	}
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| 	return p, nil
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| }
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| 
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| // Prepare prepares a raw statement parsed from parser.
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| // The statement must be prepared before it can be passed to optimize function.
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| // We pass InfoSchema instead of getting from Context in case it is changed after resolving name.
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| func Prepare(is infoschema.InfoSchema, ctx context.Context, node ast.Node) error {
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| 	ast.SetFlag(node)
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| 	if err := Preprocess(node, is, ctx); err != nil {
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| 		return errors.Trace(err)
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| 	}
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| 	if err := Validate(node, true); err != nil {
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| 		return errors.Trace(err)
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| 	}
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| 	return nil
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| }
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| 
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| // Optimizer error codes.
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| const (
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| 	CodeOneColumn           terror.ErrCode = 1
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| 	CodeSameColumns         terror.ErrCode = 2
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| 	CodeMultiWildCard       terror.ErrCode = 3
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| 	CodeUnsupported         terror.ErrCode = 4
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| 	CodeInvalidGroupFuncUse terror.ErrCode = 5
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| 	CodeIllegalReference    terror.ErrCode = 6
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| )
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| 
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| // Optimizer base errors.
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| var (
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| 	ErrOneColumn           = terror.ClassOptimizer.New(CodeOneColumn, "Operand should contain 1 column(s)")
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| 	ErrSameColumns         = terror.ClassOptimizer.New(CodeSameColumns, "Operands should contain same columns")
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| 	ErrMultiWildCard       = terror.ClassOptimizer.New(CodeMultiWildCard, "wildcard field exist more than once")
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| 	ErrUnSupported         = terror.ClassOptimizer.New(CodeUnsupported, "unsupported")
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| 	ErrInvalidGroupFuncUse = terror.ClassOptimizer.New(CodeInvalidGroupFuncUse, "Invalid use of group function")
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| 	ErrIllegalReference    = terror.ClassOptimizer.New(CodeIllegalReference, "Illegal reference")
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| )
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| 
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| func init() {
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| 	mySQLErrCodes := map[terror.ErrCode]uint16{
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| 		CodeOneColumn:           mysql.ErrOperandColumns,
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| 		CodeSameColumns:         mysql.ErrOperandColumns,
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| 		CodeMultiWildCard:       mysql.ErrParse,
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| 		CodeInvalidGroupFuncUse: mysql.ErrInvalidGroupFuncUse,
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| 		CodeIllegalReference:    mysql.ErrIllegalReference,
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| 	}
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| 	terror.ErrClassToMySQLCodes[terror.ClassOptimizer] = mySQLErrCodes
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| }
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| 
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