Documentation
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Index ¶
Constants ¶
This section is empty.
Variables ¶
This section is empty.
Functions ¶
func FindBestPlan ¶
func FindBestPlan(sctx sessionctx.Context, logical plannercore.LogicalPlan) (plannercore.Plan, error)
FindBestPlan is the optimization entrance of the cascades planner. The optimization is composed of 2 phases: exploration and implementation.
Types ¶
type Enforcer ¶
type Enforcer interface {
// NewProperty generates relaxed property with the help of enforcer.
NewProperty(prop *property.PhysicalProperty) (newProp *property.PhysicalProperty)
// OnEnforce adds physical operators on top of child implementation to satisfy
// required physical property.
OnEnforce(reqProp *property.PhysicalProperty, child memo.Implementation) (impl memo.Implementation)
// GetEnforceCost calculates cost of enforcing required physical property.
GetEnforceCost(inputCount float64) float64
}
Enforcer defines the interface for enforcer rules.
func GetEnforcerRules ¶
func GetEnforcerRules(prop *property.PhysicalProperty) (enforcers []Enforcer)
GetEnforcerRules gets all candidate enforcer rules based on required physical property.
type ImplementationRule ¶
type ImplementationRule interface {
// Match checks if current GroupExpr matches this rule under required physical property.
Match(expr *memo.GroupExpr, prop *property.PhysicalProperty) (matched bool)
// OnImplement generates physical plan using this rule for current GroupExpr. Note that
// childrenReqProps of generated physical plan should be set correspondingly in this function.
OnImplement(expr *memo.GroupExpr, reqProp *property.PhysicalProperty) (impl memo.Implementation, err error)
}
ImplementationRule defines the interface for implementation rules.
func GetImplementationRules ¶
func GetImplementationRules(node plannercore.LogicalPlan) []ImplementationRule
GetImplementationRules gets the all the candidate implementation rules based on the logical plan node.
type OrderEnforcer ¶
type OrderEnforcer struct {
}
OrderEnforcer enforces order property on child implementation.
func (*OrderEnforcer) GetEnforceCost ¶
func (e *OrderEnforcer) GetEnforceCost(inputCount float64) float64
GetEnforceCost calculates cost of sort operator.
func (*OrderEnforcer) NewProperty ¶
func (e *OrderEnforcer) NewProperty(prop *property.PhysicalProperty) (newProp *property.PhysicalProperty)
NewProperty removes order property from required physical property.
func (*OrderEnforcer) OnEnforce ¶
func (e *OrderEnforcer) OnEnforce(reqProp *property.PhysicalProperty, child memo.Implementation) (impl memo.Implementation)
OnEnforce adds sort operator to satisfy required order property.
type Transformation ¶
type Transformation interface {
GetPattern() *memo.Pattern
Match(expr *memo.ExprIter) (matched bool)
OnTransform(old *memo.ExprIter) (new *memo.GroupExpr, eraseOld bool, err error)
}
Transformation defines the interface for the transformation rules.
func GetTransformationRules ¶
func GetTransformationRules(node plannercore.LogicalPlan) []Transformation
GetTransformationRules gets the all the candidate transformation rules based on the logical plan node.
Source Files