operators

package
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 Go to latest Published: Oct 3, 2023 License: Apache-2.0 Imports: 22 Imported by: 2

Documentation

Overview

Package operators contains the operators used to plan queries.

The operators go through a few phases while planning:

  1. Logical In this first pass, we build an operator tree from the incoming parsed query. It will contain logical joins - we still haven't decided on the join algorithm to use yet. At the leaves, it will contain QueryGraphs - these are the tables in the FROM clause that we can easily do join ordering on. The logical tree will represent the full query, including projections, grouping, ordering and so on.
  2. Physical Once the logical plan has been fully built, we go bottom up and plan which routes that will be used. During this phase, we will also decide which join algorithms should be used on the vtgate level
  3. Columns & Aggregation Once we know which queries will be sent to the tablets, we go over the tree and decide which columns each operator should output. At this point, we also do offset lookups, so we know at runtime from which columns in the input table we need to read.

Index

Constants

View Source 
const VindexUnsupported = "WHERE clause for vindex function must be of the form id = <val> or id in(<val>,...)"

Variables

This section is empty.

Functions

func AddPredicate 

func AddPredicate(join JoinOp, ctx *plancontext.PlanningContext, expr sqlparser.Expr, joinPredicates bool, newFilter func(ops.Operator, sqlparser.Expr) ops.Operator) (ops.Operator, error)

func BreakExpressionInLHSandRHS 

func BreakExpressionInLHSandRHS(
	ctx *plancontext.PlanningContext,
	expr sqlparser.Expr,
	lhs semantics.TableSet,
) (bvNames []string, columns []*sqlparser.ColName, rewrittenExpr sqlparser.Expr, err error)

BreakExpressionInLHSandRHS takes an expression and extracts the parts that are coming from one of the sides into `ColName`s that are needed

func CheckValid 

func CheckValid(op ops.Operator) error

func Clone 

func Clone(op ops.Operator) ops.Operator

func Compact 

func Compact(ctx *plancontext.PlanningContext, op ops.Operator) (ops.Operator, error)

Compact will optimise the operator tree into a smaller but equivalent version

func CompareRefInt 

func CompareRefInt(a *int, b *int) bool

CompareRefInt compares two references of integers. In case either one is nil, it is considered to be smaller

func CostOf 

func CostOf(op ops.Operator) (cost int)

func PlanQuery 

func PlanQuery(ctx *plancontext.PlanningContext, selStmt sqlparser.Statement) (ops.Operator, error)

func QualifiedIdentifier 

func QualifiedIdentifier(ks *vindexes.Keyspace, i sqlparser.IdentifierCS) string

func QualifiedString 

func QualifiedString(ks *vindexes.Keyspace, s string) string

func QualifiedStrings 

func QualifiedStrings(ks *vindexes.Keyspace, ss []string) []string

func QualifiedTableName 

func QualifiedTableName(ks *vindexes.Keyspace, t sqlparser.TableName) string

func QualifiedTableNames 

func QualifiedTableNames(ks *vindexes.Keyspace, ts []sqlparser.TableName) []string

func QualifiedTables 

func QualifiedTables(ks *vindexes.Keyspace, vts []*vindexes.Table) []string

func RemovePredicate 

func RemovePredicate(ctx *plancontext.PlanningContext, expr sqlparser.Expr, op ops.Operator) (ops.Operator, error)

RemovePredicate is used when we turn a predicate into a plan operator, and the predicate needs to be removed as an AST construct

func SingleQualifiedIdentifier 

func SingleQualifiedIdentifier(ks *vindexes.Keyspace, i sqlparser.IdentifierCS) []string

func SingleQualifiedString 

func SingleQualifiedString(ks *vindexes.Keyspace, s string) []string

func SingleQualifiedTableName 

func SingleQualifiedTableName(ks *vindexes.Keyspace, t sqlparser.TableName) []string

func SortAggregations 

func SortAggregations(a []Aggr)

func SortGrouping 

func SortGrouping(a []GroupBy)

func TableID 

func TableID(op ops.Operator) (result semantics.TableSet)

func TablesUsed 

func TablesUsed(op ops.Operator) []string

func ToSQL 

func ToSQL(ctx *plancontext.PlanningContext, op ops.Operator) (sqlparser.SelectStatement, error)

func UnresolvedPredicates 

func UnresolvedPredicates(op ops.Operator, st *semantics.SemTable) (result []sqlparser.Expr)

Types

type Aggr 

type Aggr struct {
	Original *sqlparser.AliasedExpr
	Func     sqlparser.AggrFunc
	OpCode   engine.AggregateOpcode
	Alias    string
	// The index at which the user expects to see this aggregated function. Set to nil, if the user does not ask for it
	Index    *int
	Distinct bool
}

Aggr encodes all information needed for aggregation functions

type AggrRewriter 

type AggrRewriter struct {
	Err error
	// contains filtered or unexported fields
}

func (*AggrRewriter) RewriteDown 

func (ar *AggrRewriter) RewriteDown() func(sqlparser.SQLNode, sqlparser.SQLNode) bool

RewriteDown stops the walker from entering inside aggregation functions

func (*AggrRewriter) RewriteUp 

func (ar *AggrRewriter) RewriteUp() func(*sqlparser.Cursor) bool

RewriteUp will go through an expression, add aggregations to the QP, and rewrite them to use column offset

type ApplyJoin 

type ApplyJoin struct {
	LHS, RHS ops.Operator

	// Columns stores the column indexes of the columns coming from the left and right side
	// negative value comes from LHS and positive from RHS
	Columns []int

	// ColumnsAST keeps track of what AST expression is represented in the Columns array
	ColumnsAST []sqlparser.Expr

	// Vars are the arguments that need to be copied from the LHS to the RHS
	Vars map[string]int

	// LeftJoin will be true in the case of an outer join
	LeftJoin bool

	// JoinCols are the columns from the LHS used for the join.
	// These are the same columns pushed on the LHS that are now used in the Vars field
	LHSColumns []*sqlparser.ColName

	Predicate sqlparser.Expr
}

ApplyJoin is a nested loop join - for each row on the LHS, we'll execute the plan on the RHS, feeding data from left to right

func NewApplyJoin 

func NewApplyJoin(lhs, rhs ops.Operator, predicate sqlparser.Expr, leftOuterJoin bool) *ApplyJoin

func (*ApplyJoin) AddColumn 

func (a *ApplyJoin) AddColumn(ctx *plancontext.PlanningContext, expr sqlparser.Expr) (int, error)

func (*ApplyJoin) AddJoinPredicate 

func (a *ApplyJoin) AddJoinPredicate(ctx *plancontext.PlanningContext, expr sqlparser.Expr) error

func (*ApplyJoin) AddPredicate 

func (a *ApplyJoin) AddPredicate(ctx *plancontext.PlanningContext, expr sqlparser.Expr) (ops.Operator, error)

func (*ApplyJoin) Clone 

func (a *ApplyJoin) Clone(inputs []ops.Operator) ops.Operator

Clone implements the Operator interface

func (*ApplyJoin) GetLHS 

func (a *ApplyJoin) GetLHS() ops.Operator

func (*ApplyJoin) GetRHS 

func (a *ApplyJoin) GetRHS() ops.Operator

func (*ApplyJoin) IPhysical 

func (a *ApplyJoin) IPhysical()

IPhysical implements the PhysicalOperator interface

func (*ApplyJoin) Inputs 

func (a *ApplyJoin) Inputs() []ops.Operator

Inputs implements the Operator interface

func (*ApplyJoin) IsInner 

func (a *ApplyJoin) IsInner() bool

func (*ApplyJoin) MakeInner 

func (a *ApplyJoin) MakeInner()

func (*ApplyJoin) SetLHS 

func (a *ApplyJoin) SetLHS(operator ops.Operator)

func (*ApplyJoin) SetRHS 

func (a *ApplyJoin) SetRHS(operator ops.Operator)

type ColNameColumns 

type ColNameColumns interface {
	GetColumns() []*sqlparser.ColName
	AddCol(*sqlparser.ColName)
}

type CorrelatedSubQueryOp 

type CorrelatedSubQueryOp struct {
	Outer, Inner ops.Operator
	Extracted    *sqlparser.ExtractedSubquery

	// JoinCols are the columns from the LHS used for the join.
	// These are the same columns pushed on the LHS that are now used in the Vars field
	LHSColumns []*sqlparser.ColName

	// arguments that need to be copied from the outer to inner
	Vars map[string]int
	// contains filtered or unexported fields
}

func (CorrelatedSubQueryOp) AddColumn 

func (CorrelatedSubQueryOp) AddColumn(*plancontext.PlanningContext, sqlparser.Expr) (int, error)

AddColumn implements the Operator interface

func (CorrelatedSubQueryOp) AddPredicate 

func (CorrelatedSubQueryOp) AddPredicate(*plancontext.PlanningContext, sqlparser.Expr) (ops.Operator, error)

AddPredicate implements the Operator interface

func (*CorrelatedSubQueryOp) Clone 

func (c *CorrelatedSubQueryOp) Clone(inputs []ops.Operator) ops.Operator

Clone implements the Operator interface

func (*CorrelatedSubQueryOp) IPhysical 

func (c *CorrelatedSubQueryOp) IPhysical()

IPhysical implements the PhysicalOperator interface

func (*CorrelatedSubQueryOp) Inputs 

func (c *CorrelatedSubQueryOp) Inputs() []ops.Operator

Inputs implements the Operator interface

type Cost 

type Cost struct {
	VindexCost int
	IsUnique   bool
	OpCode     engine.Opcode
}

Cost is used to make it easy to compare the Cost of two plans with each other

type Delete 

type Delete struct {
	QTable           *QueryTable
	VTable           *vindexes.Table
	OwnedVindexQuery string
	AST              *sqlparser.Delete
	// contains filtered or unexported fields
}

func (Delete) AddColumn 

func (Delete) AddColumn(*plancontext.PlanningContext, sqlparser.Expr) (int, error)

AddColumn implements the Operator interface

func (Delete) AddPredicate 

func (Delete) AddPredicate(*plancontext.PlanningContext, sqlparser.Expr) (ops.Operator, error)

AddPredicate implements the Operator interface

func (*Delete) Clone 

func (d *Delete) Clone(inputs []ops.Operator) ops.Operator

Clone implements the Operator interface

func (*Delete) IPhysical 

func (d *Delete) IPhysical()

IPhysical implements the PhysicalOperator interface

func (Delete) Inputs 

func (Delete) Inputs() []ops.Operator

Inputs implements the Operator interface

func (*Delete) Introduces 

func (d *Delete) Introduces() semantics.TableSet

Introduces implements the PhysicalOperator interface

func (*Delete) TablesUsed 

func (d *Delete) TablesUsed() []string

type Derived 

type Derived struct {
	Source ops.Operator

	Query         sqlparser.SelectStatement
	Alias         string
	ColumnAliases sqlparser.Columns

	// Columns needed to feed other plans
	Columns       []*sqlparser.ColName
	ColumnsOffset []int
}

func (*Derived) AddColumn 

func (d *Derived) AddColumn(ctx *plancontext.PlanningContext, expr sqlparser.Expr) (int, error)

func (*Derived) AddPredicate 

func (d *Derived) AddPredicate(ctx *plancontext.PlanningContext, expr sqlparser.Expr) (ops.Operator, error)

func (*Derived) Clone 

func (d *Derived) Clone(inputs []ops.Operator) ops.Operator

Clone implements the Operator interface

func (*Derived) IPhysical 

func (d *Derived) IPhysical()

IPhysical implements the PhysicalOperator interface

func (*Derived) Inputs 

func (d *Derived) Inputs() []ops.Operator

Inputs implements the Operator interface

func (*Derived) IsMergeable 

func (d *Derived) IsMergeable(ctx *plancontext.PlanningContext) bool

IsMergeable is not a great name for this function. Suggestions for a better one are welcome! This function will return false if the derived table inside it has to run on the vtgate side, and so can't be merged with subqueries This logic can also be used to check if this is a derived table that can be had on the left hand side of a vtgate join. Since vtgate joins are always nested loop joins, we can't execute them on the RHS if they do some things, like LIMIT or GROUP BY on wrong columns

type Filter 

type Filter struct {
	Source     ops.Operator
	Predicates []sqlparser.Expr
}

func (*Filter) AddColumn 

func (f *Filter) AddColumn(ctx *plancontext.PlanningContext, expr sqlparser.Expr) (int, error)

func (*Filter) AddPredicate 

func (f *Filter) AddPredicate(ctx *plancontext.PlanningContext, expr sqlparser.Expr) (ops.Operator, error)

func (*Filter) Clone 

func (f *Filter) Clone(inputs []ops.Operator) ops.Operator

Clone implements the Operator interface

func (*Filter) Compact 

func (f *Filter) Compact(*plancontext.PlanningContext) (ops.Operator, rewrite.TreeIdentity, error)

func (*Filter) IPhysical 

func (f *Filter) IPhysical()

IPhysical implements the PhysicalOperator interface

func (*Filter) Inputs 

func (f *Filter) Inputs() []ops.Operator

Inputs implements the Operator interface

func (*Filter) UnsolvedPredicates 

func (f *Filter) UnsolvedPredicates(st *semantics.SemTable) []sqlparser.Expr

UnsolvedPredicates implements the unresolved interface

type GroupBy 

type GroupBy struct {
	Inner         sqlparser.Expr
	WeightStrExpr sqlparser.Expr

	// The index at which the user expects to see this column. Set to nil, if the user does not ask for it
	InnerIndex *int
	// contains filtered or unexported fields
}

GroupBy contains the expression to used in group by and also if grouping is needed at VTGate level then what the weight_string function expression to be sent down for evaluation.

func (GroupBy) AsAliasedExpr 

func (b GroupBy) AsAliasedExpr() *sqlparser.AliasedExpr

func (GroupBy) AsOrderBy 

func (b GroupBy) AsOrderBy() OrderBy

type Horizon 

type Horizon struct {
	Source ops.Operator
	Select sqlparser.SelectStatement
	// contains filtered or unexported fields
}

Horizon is an operator we use until we decide how to handle the source to the horizon. It contains information about the planning we have to do after deciding how we will send the query to the tablets.

func (Horizon) AddColumn 

func (Horizon) AddColumn(*plancontext.PlanningContext, sqlparser.Expr) (int, error)

AddColumn implements the Operator interface

func (*Horizon) AddPredicate 

func (h *Horizon) AddPredicate(ctx *plancontext.PlanningContext, expr sqlparser.Expr) (ops.Operator, error)

func (*Horizon) Clone 

func (h *Horizon) Clone(inputs []ops.Operator) ops.Operator

func (*Horizon) IPhysical 

func (h *Horizon) IPhysical()

func (*Horizon) Inputs 

func (h *Horizon) Inputs() []ops.Operator

type Join 

type Join struct {
	LHS, RHS  ops.Operator
	Predicate sqlparser.Expr
	LeftJoin  bool
	// contains filtered or unexported fields
}

Join represents a join. If we have a predicate, this is an inner join. If no predicate exists, it is a cross join

func (Join) AddColumn 

func (Join) AddColumn(*plancontext.PlanningContext, sqlparser.Expr) (int, error)

AddColumn implements the Operator interface

func (*Join) AddJoinPredicate 

func (j *Join) AddJoinPredicate(ctx *plancontext.PlanningContext, expr sqlparser.Expr) error

func (*Join) AddPredicate 

func (j *Join) AddPredicate(ctx *plancontext.PlanningContext, expr sqlparser.Expr) (ops.Operator, error)

func (*Join) Clone 

func (j *Join) Clone(inputs []ops.Operator) ops.Operator

Clone implements the Operator interface

func (*Join) Compact 

func (j *Join) Compact(ctx *plancontext.PlanningContext) (ops.Operator, rewrite.TreeIdentity, error)

func (*Join) GetLHS 

func (j *Join) GetLHS() ops.Operator

func (*Join) GetRHS 

func (j *Join) GetRHS() ops.Operator

func (*Join) Inputs 

func (j *Join) Inputs() []ops.Operator

Inputs implements the Operator interface

func (*Join) IsInner 

func (j *Join) IsInner() bool

func (*Join) MakeInner 

func (j *Join) MakeInner()

func (*Join) SetLHS 

func (j *Join) SetLHS(operator ops.Operator)

func (*Join) SetRHS 

func (j *Join) SetRHS(operator ops.Operator)

type JoinOp 

type JoinOp interface {
	ops.Operator
	GetLHS() ops.Operator
	GetRHS() ops.Operator
	SetLHS(ops.Operator)
	SetRHS(ops.Operator)
	MakeInner()
	IsInner() bool
	AddJoinPredicate(ctx *plancontext.PlanningContext, expr sqlparser.Expr) error
}

type OrderBy 

type OrderBy struct {
	Inner         *sqlparser.Order
	WeightStrExpr sqlparser.Expr
}

OrderBy contains the expression to used in order by and also if ordering is needed at VTGate level then what the weight_string function expression to be sent down for evaluation.

type QueryGraph 

type QueryGraph struct {
	// the Tables, including predicates that only depend on this particular table
	Tables []*QueryTable

	// NoDeps contains the predicates that can be evaluated anywhere.
	NoDeps sqlparser.Expr
	// contains filtered or unexported fields
}

QueryGraph represents the FROM and WHERE parts of a query. 

It is an intermediate representation of the query that makes it easier for the planner
to find all possible join combinations. Instead of storing the query information in a form that is close
to the syntax (AST), we extract the interesting parts into a graph form with the nodes being tables in the FROM
clause and the edges between them being predicates. We keep predicates in a hash map keyed by the dependencies of
the predicate. This makes it very fast to look up connections between tables in the query.

func (QueryGraph) AddColumn 

func (QueryGraph) AddColumn(*plancontext.PlanningContext, sqlparser.Expr) (int, error)

AddColumn implements the Operator interface

func (*QueryGraph) AddPredicate 

func (qg *QueryGraph) AddPredicate(ctx *plancontext.PlanningContext, expr sqlparser.Expr) (ops.Operator, error)

func (*QueryGraph) Clone 

func (qg *QueryGraph) Clone(inputs []ops.Operator) ops.Operator

Clone implements the Operator interface

func (*QueryGraph) GetPredicates 

func (qg *QueryGraph) GetPredicates(lhs, rhs semantics.TableSet) []sqlparser.Expr

GetPredicates returns the predicates that are applicable for the two given TableSets

func (QueryGraph) Inputs 

func (QueryGraph) Inputs() []ops.Operator

Inputs implements the Operator interface

func (*QueryGraph) Introduces 

func (qg *QueryGraph) Introduces() semantics.TableSet

Introduces implements the TableIDIntroducer interface

func (*QueryGraph) UnsolvedPredicates 

func (qg *QueryGraph) UnsolvedPredicates(_ *semantics.SemTable) []sqlparser.Expr

UnsolvedPredicates implements the unresolved interface

type QueryProjection 

type QueryProjection struct {
	// If you change the contents here, please update the toString() method
	SelectExprs []SelectExpr
	HasAggr     bool
	Distinct    bool

	OrderExprs         []OrderBy
	CanPushDownSorting bool
	HasStar            bool

	// AddedColumn keeps a counter for expressions added to solve HAVING expressions the user is not selecting
	AddedColumn int
	// contains filtered or unexported fields
}

QueryProjection contains the information about the projections, group by and order by expressions used to do horizon planning.

func CreateQPFromSelect 

func CreateQPFromSelect(ctx *plancontext.PlanningContext, sel *sqlparser.Select) (*QueryProjection, error)

CreateQPFromSelect creates the QueryProjection for the input *sqlparser.Select

func CreateQPFromUnion 

func CreateQPFromUnion(union *sqlparser.Union) (*QueryProjection, error)

CreateQPFromUnion creates the QueryProjection for the input *sqlparser.Union

func (*QueryProjection) AddGroupBy 

func (qp *QueryProjection) AddGroupBy(by GroupBy)

AddGroupBy does just that

func (*QueryProjection) AggrRewriter 

func (qp *QueryProjection) AggrRewriter(ctx *plancontext.PlanningContext) *AggrRewriter

AggrRewriter extracts

func (*QueryProjection) AggregationExpressions 

func (qp *QueryProjection) AggregationExpressions(ctx *plancontext.PlanningContext) (out []Aggr, err error)

func (*QueryProjection) AlignGroupByAndOrderBy 

func (qp *QueryProjection) AlignGroupByAndOrderBy(ctx *plancontext.PlanningContext)

AlignGroupByAndOrderBy aligns the group by and order by columns, so they are in the same order The GROUP BY clause is a set - the order between the elements does not make any difference, so we can simply re-arrange the column order We are also free to add more ORDER BY columns than the user asked for which we leverage, so the input is already ordered according to the GROUP BY columns used

func (*QueryProjection) FindSelectExprIndexForExpr 

func (qp *QueryProjection) FindSelectExprIndexForExpr(ctx *plancontext.PlanningContext, expr sqlparser.Expr) (*int, *sqlparser.AliasedExpr)

FindSelectExprIndexForExpr returns the index of the given expression in the select expressions, if it is part of it returns -1 otherwise.

func (*QueryProjection) GetColumnCount 

func (qp *QueryProjection) GetColumnCount() int

func (*QueryProjection) GetGrouping 

func (qp *QueryProjection) GetGrouping() []GroupBy

GetGrouping returns a copy of the grouping parameters of the QP

func (*QueryProjection) GetSimplifiedExpr 

func (qp *QueryProjection) GetSimplifiedExpr(e sqlparser.Expr) (expr sqlparser.Expr, weightStrExpr sqlparser.Expr, err error)

GetSimplifiedExpr takes an expression used in ORDER BY or GROUP BY, and returns an expression that is simpler to evaluate

func (*QueryProjection) NeedsAggregation 

func (qp *QueryProjection) NeedsAggregation() bool

NeedsAggregation returns true if we either have aggregate functions or grouping defined

func (*QueryProjection) NeedsDistinct 

func (qp *QueryProjection) NeedsDistinct() bool

NeedsDistinct returns true if the query needs explicit distinct

func (*QueryProjection) NeedsProjecting added in v0.16.1 

func (qp *QueryProjection) NeedsProjecting(
	ctx *plancontext.PlanningContext,
	pusher func(expr *sqlparser.AliasedExpr) (int, error),
) (needsVtGateEval bool, expressions []sqlparser.Expr, colNames []string, err error)

NeedsProjecting returns true if we have projections that need to be evaluated at the vtgate level and can't be pushed down to MySQL

type QueryTable 

type QueryTable struct {
	ID          semantics.TableSet
	Alias       *sqlparser.AliasedTableExpr
	Table       sqlparser.TableName
	Predicates  []sqlparser.Expr
	IsInfSchema bool
}

QueryTable is a single FROM table, including all predicates particular to this table This is to be used as an immutable data structure which is created in the logical Operator Tree

func (*QueryTable) Clone 

func (qt *QueryTable) Clone() *QueryTable

Clone implements the Operator interface

type Route 

type Route struct {
	Source ops.Operator

	RouteOpCode engine.Opcode
	Keyspace    *vindexes.Keyspace

	// here we store the possible vindexes we can use so that when we add predicates to the plan,
	// we can quickly check if the new predicates enables any new vindex Options
	VindexPreds []*VindexPlusPredicates

	// the best option available is stored here
	Selected *VindexOption

	// The following two fields are used when routing information_schema queries
	SysTableTableSchema []evalengine.Expr
	SysTableTableName   map[string]evalengine.Expr

	// SeenPredicates contains all the predicates that have had a chance to influence routing.
	// If we need to replan routing, we'll use this list
	SeenPredicates []sqlparser.Expr

	// TargetDestination specifies an explicit target destination tablet type
	TargetDestination key.Destination

	// Alternates contains alternate routes to equivalent sources in
	// other keyspaces.
	Alternates map[*vindexes.Keyspace]*Route

	// Routes that have been merged into this one.
	MergedWith []*Route
}

func (*Route) AddColumn 

func (r *Route) AddColumn(ctx *plancontext.PlanningContext, e sqlparser.Expr) (int, error)

func (*Route) AddPredicate 

func (r *Route) AddPredicate(ctx *plancontext.PlanningContext, expr sqlparser.Expr) (ops.Operator, error)

func (*Route) AlternateInKeyspace 

func (r *Route) AlternateInKeyspace(keyspace *vindexes.Keyspace) *Route

func (*Route) Clone 

func (r *Route) Clone(inputs []ops.Operator) ops.Operator

Clone implements the Operator interface

func (*Route) Cost 

func (r *Route) Cost() int

Cost implements the Operator interface

func (*Route) IPhysical 

func (*Route) IPhysical()

IPhysical implements the PhysicalOperator interface

func (*Route) Inputs 

func (r *Route) Inputs() []ops.Operator

Inputs implements the Operator interface

func (*Route) IsSingleShard 

func (r *Route) IsSingleShard() bool

func (*Route) PickBestAvailableVindex 

func (r *Route) PickBestAvailableVindex()

PickBestAvailableVindex goes over the available vindexes for this route and picks the best one available.

func (*Route) SelectedVindex 

func (r *Route) SelectedVindex() vindexes.Vindex

func (*Route) TablesUsed 

func (r *Route) TablesUsed() []string

TablesUsed returns tables used by MergedWith routes, which are not included in Inputs() and thus not a part of the operator tree

func (*Route) UpdateRoutingLogic 

func (r *Route) UpdateRoutingLogic(ctx *plancontext.PlanningContext, expr sqlparser.Expr) error

func (*Route) VindexExpressions 

func (r *Route) VindexExpressions() []sqlparser.Expr

type SelectExpr 

type SelectExpr struct {
	Col  sqlparser.SelectExpr
	Aggr bool
}

SelectExpr provides whether the columns is aggregation expression or not.

func (SelectExpr) GetAliasedExpr 

func (s SelectExpr) GetAliasedExpr() (*sqlparser.AliasedExpr, error)

GetAliasedExpr returns the SelectExpr as a *sqlparser.AliasedExpr if its type allows it, otherwise an error is returned.

func (SelectExpr) GetExpr 

func (s SelectExpr) GetExpr() (sqlparser.Expr, error)

GetExpr returns the underlying sqlparser.Expr of our SelectExpr

type SubQuery 

type SubQuery struct {
	Outer ops.Operator
	Inner []*SubQueryInner
	// contains filtered or unexported fields
}

SubQuery stores the information about subquery

func (SubQuery) AddColumn 

func (SubQuery) AddColumn(*plancontext.PlanningContext, sqlparser.Expr) (int, error)

AddColumn implements the Operator interface

func (SubQuery) AddPredicate 

func (SubQuery) AddPredicate(*plancontext.PlanningContext, sqlparser.Expr) (ops.Operator, error)

AddPredicate implements the Operator interface

func (*SubQuery) Clone 

func (s *SubQuery) Clone(inputs []ops.Operator) ops.Operator

Clone implements the Operator interface

func (*SubQuery) Inputs 

func (s *SubQuery) Inputs() []ops.Operator

Inputs implements the Operator interface

type SubQueryInner 

type SubQueryInner struct {
	// Inner is the Operator inside the parenthesis of the subquery.
	// i.e: select (select 1 union select 1), the Inner here would be
	// of type Concatenate since we have a Union.
	Inner ops.Operator

	// ExtractedSubquery contains all information we need about this subquery
	ExtractedSubquery *sqlparser.ExtractedSubquery
	// contains filtered or unexported fields
}

SubQueryInner stores the subquery information for a select statement

func (SubQueryInner) AddColumn 

func (SubQueryInner) AddColumn(*plancontext.PlanningContext, sqlparser.Expr) (int, error)

AddColumn implements the Operator interface

func (SubQueryInner) AddPredicate 

func (SubQueryInner) AddPredicate(*plancontext.PlanningContext, sqlparser.Expr) (ops.Operator, error)

AddPredicate implements the Operator interface

func (*SubQueryInner) Clone 

func (s *SubQueryInner) Clone(inputs []ops.Operator) ops.Operator

Clone implements the Operator interface

func (*SubQueryInner) Inputs 

func (s *SubQueryInner) Inputs() []ops.Operator

Inputs implements the Operator interface

type SubQueryOp 

type SubQueryOp struct {
	Outer, Inner ops.Operator
	Extracted    *sqlparser.ExtractedSubquery
	// contains filtered or unexported fields
}

func (SubQueryOp) AddColumn 

func (SubQueryOp) AddColumn(*plancontext.PlanningContext, sqlparser.Expr) (int, error)

AddColumn implements the Operator interface

func (SubQueryOp) AddPredicate 

func (SubQueryOp) AddPredicate(*plancontext.PlanningContext, sqlparser.Expr) (ops.Operator, error)

AddPredicate implements the Operator interface

func (*SubQueryOp) Clone 

func (s *SubQueryOp) Clone(inputs []ops.Operator) ops.Operator

Clone implements the Operator interface

func (*SubQueryOp) IPhysical 

func (s *SubQueryOp) IPhysical()

IPhysical implements the PhysicalOperator interface

func (*SubQueryOp) Inputs 

func (s *SubQueryOp) Inputs() []ops.Operator

Inputs implements the Operator interface

type Table 

type Table struct {
	QTable  *QueryTable
	VTable  *vindexes.Table
	Columns []*sqlparser.ColName
	// contains filtered or unexported fields
}

func (*Table) AddCol 

func (to *Table) AddCol(col *sqlparser.ColName)

func (*Table) AddColumn 

func (to *Table) AddColumn(_ *plancontext.PlanningContext, e sqlparser.Expr) (int, error)

func (*Table) AddPredicate 

func (to *Table) AddPredicate(_ *plancontext.PlanningContext, expr sqlparser.Expr) (ops.Operator, error)

AddPredicate implements the PhysicalOperator interface

func (*Table) Clone 

func (to *Table) Clone([]ops.Operator) ops.Operator

Clone implements the Operator interface

func (*Table) GetColumns 

func (to *Table) GetColumns() []*sqlparser.ColName

func (*Table) IPhysical 

func (to *Table) IPhysical()

IPhysical implements the PhysicalOperator interface

func (Table) Inputs 

func (Table) Inputs() []ops.Operator

Inputs implements the Operator interface

func (*Table) Introduces 

func (to *Table) Introduces() semantics.TableSet

Introduces implements the PhysicalOperator interface

func (*Table) TablesUsed 

func (to *Table) TablesUsed() []string

type TableIDIntroducer 

type TableIDIntroducer interface {
	Introduces() semantics.TableSet
}

TableIDIntroducer is used to signal that this operator introduces data from a new source

type TableUser 

type TableUser interface {
	TablesUsed() []string
}

TableUser is used to signal that this operator directly interacts with one or more tables

type Union 

type Union struct {
	Sources  []ops.Operator
	Distinct bool

	// TODO this should be removed. For now it's used to fail queries
	Ordering sqlparser.OrderBy
	// contains filtered or unexported fields
}

func (Union) AddColumn 

func (Union) AddColumn(*plancontext.PlanningContext, sqlparser.Expr) (int, error)

AddColumn implements the Operator interface

func (*Union) AddPredicate 

func (u *Union) AddPredicate(ctx *plancontext.PlanningContext, expr sqlparser.Expr) (ops.Operator, error)

AddPredicate adds a predicate a UNION by pushing the predicate to all sources of the UNION. 

this is done by offset and expression rewriting. Say we have a query like so:

select * ( 

 	select foo as col, bar from tbl1
	union
	select id, baz from tbl2

) as X where X.col = 42

We want to push down the `X.col = 42` as far down the operator tree as possible. We want to end up with an operator tree that looks something like this:

select * ( 

 	select foo as col, bar from tbl1 where foo = 42
	union
	select id, baz from tbl2 where id = 42

) as X

Notice how `X.col = 42` has been translated to `foo = 42` and `id = 42` on respective WHERE clause. The first SELECT of the union dictates the column names, and the second is whatever expression can be found on the same offset. The names of the RHS are discarded.

func (*Union) Clone 

func (u *Union) Clone(inputs []ops.Operator) ops.Operator

Clone implements the Operator interface

func (*Union) Compact 

func (u *Union) Compact(*plancontext.PlanningContext) (ops.Operator, rewrite.TreeIdentity, error)

func (*Union) GetSelectFor 

func (u *Union) GetSelectFor(source int) (*sqlparser.Select, error)

func (*Union) IPhysical 

func (u *Union) IPhysical()

IPhysical implements the PhysicalOperator interface

func (*Union) Inputs 

func (u *Union) Inputs() []ops.Operator

Inputs implements the Operator interface

type Update 

type Update struct {
	QTable              *QueryTable
	VTable              *vindexes.Table
	Assignments         map[string]sqlparser.Expr
	ChangedVindexValues map[string]*engine.VindexValues
	OwnedVindexQuery    string
	AST                 *sqlparser.Update
	// contains filtered or unexported fields
}

func (Update) AddColumn 

func (Update) AddColumn(*plancontext.PlanningContext, sqlparser.Expr) (int, error)

AddColumn implements the Operator interface

func (Update) AddPredicate 

func (Update) AddPredicate(*plancontext.PlanningContext, sqlparser.Expr) (ops.Operator, error)

AddPredicate implements the Operator interface

func (*Update) Clone 

func (u *Update) Clone(inputs []ops.Operator) ops.Operator

Clone implements the Operator interface

func (*Update) IPhysical 

func (u *Update) IPhysical()

IPhysical implements the PhysicalOperator interface

func (Update) Inputs 

func (Update) Inputs() []ops.Operator

Inputs implements the Operator interface

func (*Update) Introduces 

func (u *Update) Introduces() semantics.TableSet

Introduces implements the PhysicalOperator interface

func (*Update) TablesUsed 

func (u *Update) TablesUsed() []string

type Vindex 

type Vindex struct {
	OpCode  engine.VindexOpcode
	Table   VindexTable
	Vindex  vindexes.Vindex
	Solved  semantics.TableSet
	Columns []*sqlparser.ColName
	Value   sqlparser.Expr
	// contains filtered or unexported fields
}

func (*Vindex) AddCol 

func (v *Vindex) AddCol(col *sqlparser.ColName)

func (*Vindex) AddColumn 

func (v *Vindex) AddColumn(_ *plancontext.PlanningContext, expr sqlparser.Expr) (int, error)

func (*Vindex) AddPredicate 

func (v *Vindex) AddPredicate(ctx *plancontext.PlanningContext, expr sqlparser.Expr) (ops.Operator, error)

func (*Vindex) CheckValid 

func (v *Vindex) CheckValid() error

checkValid implements the Operator interface

func (*Vindex) Clone 

func (v *Vindex) Clone([]ops.Operator) ops.Operator

Clone implements the Operator interface

func (*Vindex) GetColumns 

func (v *Vindex) GetColumns() []*sqlparser.ColName

func (*Vindex) IPhysical 

func (v *Vindex) IPhysical()

IPhysical implements the PhysicalOperator interface

func (Vindex) Inputs 

func (Vindex) Inputs() []ops.Operator

Inputs implements the Operator interface

func (*Vindex) Introduces 

func (v *Vindex) Introduces() semantics.TableSet

Introduces implements the Operator interface

func (*Vindex) TablesUsed 

func (v *Vindex) TablesUsed() []string

TablesUsed implements the Operator interface. It is not keyspace-qualified.

type VindexOption 

type VindexOption struct {
	Ready  bool
	Values []evalengine.Expr
	// columns that we have seen so far. Used only for multi-column vindexes so that we can track how many columns part of the vindex we have seen
	ColsSeen    map[string]any
	ValueExprs  []sqlparser.Expr
	Predicates  []sqlparser.Expr
	OpCode      engine.Opcode
	FoundVindex vindexes.Vindex
	Cost        Cost
}

VindexOption stores the information needed to know if we have all the information needed to use a vindex

type VindexPlusPredicates 

type VindexPlusPredicates struct {
	TableID   semantics.TableSet
	ColVindex *vindexes.ColumnVindex

	// during planning, we store the alternatives found for this route in this slice
	Options []*VindexOption
}

VindexPlusPredicates is a struct used to store all the predicates that the vindex can be used to query

type VindexTable 

type VindexTable struct {
	TableID    semantics.TableSet
	Alias      *sqlparser.AliasedTableExpr
	Table      sqlparser.TableName
	Predicates []sqlparser.Expr
	VTable     *vindexes.Table
}

VindexTable contains information about the vindex table we want to query

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