vitess.io/vitess@v0.16.2/go/vt/vtgate/planbuilder/operators/correlated_subquery.go (about)

     1  /*
     2  Copyright 2022 The Vitess Authors.
     3  
     4  Licensed under the Apache License, Version 2.0 (the "License");
     5  you may not use this file except in compliance with the License.
     6  You may obtain a copy of the License at
     7  
     8      http://www.apache.org/licenses/LICENSE-2.0
     9  
    10  Unless required by applicable law or agreed to in writing, software
    11  distributed under the License is distributed on an "AS IS" BASIS,
    12  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
    13  See the License for the specific language governing permissions and
    14  limitations under the License.
    15  */
    16  
    17  package operators
    18  
    19  import (
    20  	"vitess.io/vitess/go/vt/sqlparser"
    21  	"vitess.io/vitess/go/vt/vtgate/planbuilder/operators/ops"
    22  )
    23  
    24  type (
    25  	CorrelatedSubQueryOp struct {
    26  		Outer, Inner ops.Operator
    27  		Extracted    *sqlparser.ExtractedSubquery
    28  
    29  		// JoinCols are the columns from the LHS used for the join.
    30  		// These are the same columns pushed on the LHS that are now used in the Vars field
    31  		LHSColumns []*sqlparser.ColName
    32  
    33  		// arguments that need to be copied from the outer to inner
    34  		Vars map[string]int
    35  
    36  		noColumns
    37  		noPredicates
    38  	}
    39  
    40  	SubQueryOp struct {
    41  		Outer, Inner ops.Operator
    42  		Extracted    *sqlparser.ExtractedSubquery
    43  
    44  		noColumns
    45  		noPredicates
    46  	}
    47  )
    48  
    49  var _ ops.PhysicalOperator = (*SubQueryOp)(nil)
    50  var _ ops.PhysicalOperator = (*CorrelatedSubQueryOp)(nil)
    51  
    52  // IPhysical implements the PhysicalOperator interface
    53  func (s *SubQueryOp) IPhysical() {}
    54  
    55  // Clone implements the Operator interface
    56  func (s *SubQueryOp) Clone(inputs []ops.Operator) ops.Operator {
    57  	result := &SubQueryOp{
    58  		Outer:     inputs[0],
    59  		Inner:     inputs[1],
    60  		Extracted: s.Extracted,
    61  	}
    62  	return result
    63  }
    64  
    65  // Inputs implements the Operator interface
    66  func (s *SubQueryOp) Inputs() []ops.Operator {
    67  	return []ops.Operator{s.Outer, s.Inner}
    68  }
    69  
    70  // IPhysical implements the PhysicalOperator interface
    71  func (c *CorrelatedSubQueryOp) IPhysical() {}
    72  
    73  // Clone implements the Operator interface
    74  func (c *CorrelatedSubQueryOp) Clone(inputs []ops.Operator) ops.Operator {
    75  	columns := make([]*sqlparser.ColName, len(c.LHSColumns))
    76  	copy(columns, c.LHSColumns)
    77  	vars := make(map[string]int, len(c.Vars))
    78  	for k, v := range c.Vars {
    79  		vars[k] = v
    80  	}
    81  
    82  	result := &CorrelatedSubQueryOp{
    83  		Outer:      inputs[0],
    84  		Inner:      inputs[1],
    85  		Extracted:  c.Extracted,
    86  		LHSColumns: columns,
    87  		Vars:       vars,
    88  	}
    89  	return result
    90  }
    91  
    92  // Inputs implements the Operator interface
    93  func (c *CorrelatedSubQueryOp) Inputs() []ops.Operator {
    94  	return []ops.Operator{c.Outer, c.Inner}
    95  }