tidb: github.com/pingcap/tidb/planner/memo Index | Files

package memo

import "github.com/pingcap/tidb/planner/memo"

Index

Package Files

expr_iterator.go group.go group_expr.go implementation.go pattern.go

Constants

const (
    // EngineTiDBOnly is the EngineTypeSet for EngineTiDB only.
    EngineTiDBOnly = EngineTypeSet(EngineTiDB)
    // EngineTiKVOnly is the EngineTypeSet for EngineTiKV only.
    EngineTiKVOnly = EngineTypeSet(EngineTiKV)
    // EngineTiFlashOnly is the EngineTypeSet for EngineTiFlash only.
    EngineTiFlashOnly = EngineTypeSet(EngineTiFlash)
    // EngineTiKVOrTiFlash is the EngineTypeSet for (EngineTiKV | EngineTiFlash).
    EngineTiKVOrTiFlash = EngineTypeSet(EngineTiKV | EngineTiFlash)
    // EngineAll is the EngineTypeSet for all of the EngineTypes.
    EngineAll = EngineTypeSet(EngineTiDB | EngineTiKV | EngineTiFlash)
)

type EngineType Uses

type EngineType uint

EngineType is determined by whether it's above or below `Gather`s. Plan will choose the different engine to be implemented/executed on according to its EngineType. Different engine may support different operators with different cost, so we should design different transformation and implementation rules for each engine.

const (
    // EngineTiDB stands for groups which is above `Gather`s and will be executed in TiDB layer.
    EngineTiDB EngineType = 1 << iota
    // EngineTiKV stands for groups which is below `Gather`s and will be executed in TiKV layer.
    EngineTiKV
    // EngineTiFlash stands for groups which is below `Gather`s and will be executed in TiFlash layer.
    EngineTiFlash
)

func (EngineType) String Uses

func (e EngineType) String() string

String implements fmt.Stringer interface.

type EngineTypeSet Uses

type EngineTypeSet uint

EngineTypeSet is the bit set of EngineTypes.

func (EngineTypeSet) Contains Uses

func (e EngineTypeSet) Contains(tp EngineType) bool

Contains checks whether the EngineTypeSet contains the EngineType.

type ExprIter Uses

type ExprIter struct {
    // Group and Element solely identify a Group expression.
    *Group
    *list.Element

    // Pattern describes the node of pattern tree.
    // The Operand type of the Group expression and the EngineType of the Group
    // must be matched with it.
    *Pattern

    // Children is used to iterate the child expressions.
    Children []*ExprIter
    // contains filtered or unexported fields
}

ExprIter enumerates all the equivalent expressions in the Group according to the expression pattern.

func NewExprIterFromGroupElem Uses

func NewExprIterFromGroupElem(elem *list.Element, p *Pattern) *ExprIter

NewExprIterFromGroupElem creates the iterator on the Group Element.

func (*ExprIter) GetExpr Uses

func (iter *ExprIter) GetExpr() *GroupExpr

GetExpr returns the root GroupExpr of the iterator.

func (*ExprIter) Matched Uses

func (iter *ExprIter) Matched() bool

Matched returns whether the iterator founds a Group expression matches the pattern.

func (*ExprIter) Next Uses

func (iter *ExprIter) Next() (found bool)

Next returns the next Group expression matches the pattern.

func (*ExprIter) Reset Uses

func (iter *ExprIter) Reset() (findMatch bool)

Reset resets the iterator to the first matched Group expression.

type Group Uses

type Group struct {
    Equivalents *list.List

    FirstExpr    map[Operand]*list.Element
    Fingerprints map[string]*list.Element

    Explored        bool
    SelfFingerprint string

    ImplMap map[string]Implementation
    Prop    *property.LogicalProperty

    EngineType EngineType
}

Group is short for expression Group, which is used to store all the logically equivalent expressions. It's a set of GroupExpr.

func NewGroupWithSchema Uses

func NewGroupWithSchema(e *GroupExpr, s *expression.Schema) *Group

NewGroupWithSchema creates a new Group with given schema.

func (*Group) Delete Uses

func (g *Group) Delete(e *GroupExpr)

Delete an existing Group expression.

func (*Group) Exists Uses

func (g *Group) Exists(e *GroupExpr) bool

Exists checks whether a Group expression existed in a Group.

func (*Group) FingerPrint Uses

func (g *Group) FingerPrint() string

FingerPrint returns the unique fingerprint of the Group.

func (*Group) GetFirstElem Uses

func (g *Group) GetFirstElem(operand Operand) *list.Element

GetFirstElem returns the first Group expression which matches the Operand. Return a nil pointer if there isn't.

func (*Group) GetImpl Uses

func (g *Group) GetImpl(prop *property.PhysicalProperty) Implementation

GetImpl returns the best Implementation satisfy the physical property.

func (*Group) Insert Uses

func (g *Group) Insert(e *GroupExpr) bool

Insert a nonexistent Group expression.

func (*Group) InsertImpl Uses

func (g *Group) InsertImpl(prop *property.PhysicalProperty, impl Implementation)

InsertImpl inserts the best Implementation satisfy the physical property.

func (*Group) SetEngineType Uses

func (g *Group) SetEngineType(e EngineType) *Group

SetEngineType sets the engine type of the group.

type GroupExpr Uses

type GroupExpr struct {
    ExprNode plannercore.LogicalPlan
    Children []*Group
    Explored bool
    Group    *Group
    // contains filtered or unexported fields
}

GroupExpr is used to store all the logically equivalent expressions which have the same root operator. Different from a normal expression, the Children of a Group expression are expression Groups, not expressions. Another property of Group expression is that the child Group references will never be changed once the Group expression is created.

func NewGroupExpr Uses

func NewGroupExpr(node plannercore.LogicalPlan) *GroupExpr

NewGroupExpr creates a GroupExpr based on a logical plan node.

func (*GroupExpr) FingerPrint Uses

func (e *GroupExpr) FingerPrint() string

FingerPrint gets the unique fingerprint of the Group expression.

func (*GroupExpr) SetChildren Uses

func (e *GroupExpr) SetChildren(children ...*Group)

SetChildren sets Children of the GroupExpr.

type Implementation Uses

type Implementation interface {
    CalcCost(outCount float64, children ...Implementation) float64
    SetCost(cost float64)
    GetCost() float64
    GetPlan() plannercore.PhysicalPlan

    // AttachChildren is used to attach children implementations and returns it self.
    AttachChildren(children ...Implementation) Implementation
}

Implementation defines the interface for cost of physical plan.

type Operand Uses

type Operand int

Operand is the node of a pattern tree, it represents a logical expression operator. Different from logical plan operator which holds the full information about an expression operator, Operand only stores the type information. An Operand may correspond to a concrete logical plan operator, or it can has special meaning, e.g, a placeholder for any logical plan operator.

const (
    // OperandAny is a placeholder for any Operand.
    OperandAny Operand = iota
    // OperandJoin is the operand for LogicalJoin.
    OperandJoin
    // OperandAggregation is the operand for LogicalAggregation.
    OperandAggregation
    // OperandProjection is the operand for LogicalProjection.
    OperandProjection
    // OperandSelection is the operand for LogicalSelection.
    OperandSelection
    // OperandApply is the operand for LogicalApply.
    OperandApply
    // OperandMaxOneRow is the operand for LogicalMaxOneRow.
    OperandMaxOneRow
    // OperandTableDual is the operand for LogicalTableDual.
    OperandTableDual
    // OperandDataSource is the operand for DataSource.
    OperandDataSource
    // OperandUnionScan is the operand for LogicalUnionScan.
    OperandUnionScan
    // OperandUnionAll is the operand for LogicalUnionAll.
    OperandUnionAll
    // OperandSort is the operand for LogicalSort.
    OperandSort
    // OperandTopN is the operand for LogicalTopN.
    OperandTopN
    // OperandLock is the operand for LogicalLock.
    OperandLock
    // OperandLimit is the operand for LogicalLimit.
    OperandLimit
    // OperandTableGather is the operand for TableGather.
    OperandTableGather
    // OperandTableScan is the operand for TableScan.
    OperandTableScan
    // OperandShow is the operand for Show.
    OperandShow
    // OperandUnsupported is the operand for unsupported operators.
    OperandUnsupported
)

func GetOperand Uses

func GetOperand(p plannercore.LogicalPlan) Operand

GetOperand maps logical plan operator to Operand.

func (Operand) Match Uses

func (o Operand) Match(t Operand) bool

Match checks if current Operand matches specified one.

type Pattern Uses

type Pattern struct {
    Operand
    EngineTypeSet
    Children []*Pattern
}

Pattern defines the match pattern for a rule. It's a tree-like structure which is a piece of a logical expression. Each node in the Pattern tree is defined by an Operand and EngineType pair.

func BuildPattern Uses

func BuildPattern(operand Operand, engineTypeSet EngineTypeSet, children ...*Pattern) *Pattern

BuildPattern builds a Pattern from Operand, EngineType and child Patterns. Used in GetPattern() of Transformation interface to generate a Pattern.

func NewPattern Uses

func NewPattern(operand Operand, engineTypeSet EngineTypeSet) *Pattern

NewPattern creates a pattern node according to the Operand and EngineType.

func (*Pattern) Match Uses

func (p *Pattern) Match(o Operand, e EngineType) bool

Match checks whether the EngineTypeSet contains the given EngineType and whether the two Operands match.

func (*Pattern) MatchOperandAny Uses

func (p *Pattern) MatchOperandAny(e EngineType) bool

MatchOperandAny checks whether the pattern's Operand is OperandAny and the EngineTypeSet contains the given EngineType.

func (*Pattern) SetChildren Uses

func (p *Pattern) SetChildren(children ...*Pattern)

SetChildren sets the Children information for a pattern node.

Package memo imports 5 packages (graph) and is imported by 4 packages. Updated 2019-11-11. Refresh now. Tools for package owners.