code: func (b *executorBuilder) corColInAccess(p plannercore.PhysicalPlan) bool {
  	var access []expression.Expression
  	switch x := p.(type) {
  	case *plannercore.PhysicalTableScan:
  		access = x.AccessCondition
  	case *plannercore.PhysicalIndexScan:
  		access = x.AccessCondition
  	}
  	for _, cond := range access {
  		if len(expression.ExtractCorColumns(cond)) > 0 {
  			return true
  		}
  	}
  	return false
  }
docs: // corColInAccess checks whether there's correlated column in access conditions.