planbuilder

Documentation

Overview

Package planbuilder allows you to build execution plans that describe how to fulfill a query that may span multiple keyspaces or shards. The main entry points for this package are Build and BuildFromStmt.

Index

• Constants
• Variables
• func BuildColName(rcs []*resultColumn, index int) (*sqlparser.ColName, error)
• func BuildFromStmt(query string, stmt sqlparser.Statement, vschema ContextVSchema, ...) (*engine.Plan, error)
• func First(input logicalPlan) logicalPlan
• func ResultFromNumber(rcs []*resultColumn, val *sqlparser.Literal) (int, error)
• func TestBuilder(query string, vschema ContextVSchema) (*engine.Plan, error)
• type ContextVSchema

Constants

const (
	ViewDifferentKeyspace string = "Select query does not belong to the same keyspace as the view statement"
	ViewComplex           string = "Complex select queries are not supported in create or alter view statements"
)

Error messages for CreateView queries

Variables

var ErrPlanNotSupported = errors.New("plan building not supported")

ErrPlanNotSupported is an error for plan building not supported

Functions

func BuildColName

func BuildColName(rcs []*resultColumn, index int) (*sqlparser.ColName, error)

BuildColName builds a *sqlparser.ColName for the resultColumn specified by the index. The built ColName will correctly reference the resultColumn it was built from.

func BuildFromStmt

func BuildFromStmt(query string, stmt sqlparser.Statement, vschema ContextVSchema, bindVarNeeds *sqlparser.BindVarNeeds) (*engine.Plan, error)

BuildFromStmt builds a plan based on the AST provided.

func First

func First(input logicalPlan) logicalPlan

First returns the first logical plan of the tree, which is usually the left most leaf.

func ResultFromNumber

func ResultFromNumber(rcs []*resultColumn, val *sqlparser.Literal) (int, error)

ResultFromNumber returns the result column index based on the column order expression.

func TestBuilder

func TestBuilder(query string, vschema ContextVSchema) (*engine.Plan, error)

TestBuilder builds a plan for a query based on the specified vschema. This method is only used from tests

Types

type ContextVSchema

type ContextVSchema interface {
	FindTable(tablename sqlparser.TableName) (*vindexes.Table, string, topodatapb.TabletType, key.Destination, error)
	FindTableOrVindex(tablename sqlparser.TableName) (*vindexes.Table, vindexes.Vindex, string, topodatapb.TabletType, key.Destination, error)
	DefaultKeyspace() (*vindexes.Keyspace, error)
	TargetString() string
	Destination() key.Destination
	TabletType() topodatapb.TabletType
	TargetDestination(qualifier string) (key.Destination, *vindexes.Keyspace, topodatapb.TabletType, error)
	AnyKeyspace() (*vindexes.Keyspace, error)
	FirstSortedKeyspace() (*vindexes.Keyspace, error)
	SysVarSetEnabled() bool
	KeyspaceExists(keyspace string) bool
	AllKeyspace() ([]*vindexes.Keyspace, error)
}

ContextVSchema defines the interface for this package to fetch info about tables.