vtexplain

Documentation

Overview

Package vtexplain analyzes a set of sql statements and returns the corresponding vtgate and vttablet query plans that will be executed on the given statements

Package vtexplain analyzes a set of sql statements and returns the corresponding vtgate and vttablet query plans that will be executed on the given statements

Index

• Constants
• func ExplainsAsJSON(explains []*Explain) string
• func ExplainsAsText(explains []*Explain) string
• func Init(vSchemaStr, sqlSchema string, opts *Options) error
• type ExecutorMode
• type Explain
  • func Run(sql string) ([]*Explain, error)
• type ExplainTopo
  • func (et *ExplainTopo) GetSrvKeyspace(ctx context.Context, cell, keyspace string) (*topodatapb.SrvKeyspace, error)
  • func (et *ExplainTopo) GetSrvKeyspaceNames(ctx context.Context, cell string) ([]string, error)
  • func (et *ExplainTopo) GetTopoServer() *topo.Server
  • func (et *ExplainTopo) WatchSrvVSchema(ctx context.Context, cell string, callback func(*vschemapb.SrvVSchema, error))
• type MysqlQuery
• type Options
• type TabletActions
• type TabletQuery
  • func (tq *TabletQuery) MarshalJSON() ([]byte, error)

Constants

const (
	// ModeMulti is the default mode with autocommit implemented at vtgate
	ModeMulti = "multi"

	// ModeTwoPC enables the twopc feature
	ModeTwoPC = "twopc"
)

Functions

func ExplainsAsJSON

func ExplainsAsJSON(explains []*Explain) string

ExplainsAsJSON returns a json representation of the explains

func ExplainsAsText

func ExplainsAsText(explains []*Explain) string

ExplainsAsText returns a text representation of the explains in logical time order

func Init

func Init(vSchemaStr, sqlSchema string, opts *Options) error

Init sets up the fake execution environment

Types

type ExecutorMode

type ExecutorMode string

ExecutorMode controls the mode of operation for the vtexplain simulator

type Explain

type Explain struct {
	// original sql statement
	SQL string

	// the vtgate plan(s)
	Plans []*engine.Plan

	// list of queries / bind vars sent to each tablet
	TabletActions map[string]*TabletActions
}

Explain defines how vitess will execute a given sql query, including the vtgate query plans and all queries run on each tablet.

func Run

func Run(sql string) ([]*Explain, error)

Run the explain analysis on the given queries

type ExplainTopo

type ExplainTopo struct {
	// Map of keyspace name to vschema
	Keyspaces map[string]*vschemapb.Keyspace

	// Map of ks/shard to test tablet connection
	TabletConns map[string]*explainTablet

	// Synchronization lock
	Lock sync.Mutex

	// Number of shards for sharded keyspaces
	NumShards int
}

ExplainTopo satisfies the srvtopo.Server interface. Modeled after the vtgate test sandboxTopo

func (*ExplainTopo) GetSrvKeyspace

func (et *ExplainTopo) GetSrvKeyspace(ctx context.Context, cell, keyspace string) (*topodatapb.SrvKeyspace, error)

GetSrvKeyspace is part of the srvtopo.Server interface.

func (*ExplainTopo) GetSrvKeyspaceNames

func (et *ExplainTopo) GetSrvKeyspaceNames(ctx context.Context, cell string) ([]string, error)

GetSrvKeyspaceNames is part of the srvtopo.Server interface.

func (*ExplainTopo) GetTopoServer

func (et *ExplainTopo) GetTopoServer() *topo.Server

GetTopoServer is part of the srvtopo.Server interface

func (*ExplainTopo) WatchSrvVSchema

func (et *ExplainTopo) WatchSrvVSchema(ctx context.Context, cell string, callback func(*vschemapb.SrvVSchema, error))

WatchSrvVSchema is part of the srvtopo.Server interface.

type MysqlQuery

type MysqlQuery struct {
	// Sequence number of the query
	Time int

	// SQL command sent to the given tablet
	SQL string
}

MysqlQuery defines a query that was sent to a given tablet and how it was processed in mysql

type Options

type Options struct {
	// NumShards indicates the number of shards in the topology
	NumShards int

	// ReplicationMode must be set to either "ROW" or "STATEMENT" before
	// initialization
	ReplicationMode string

	// Normalize controls whether or not vtgate does query normalization
	Normalize bool

	// ExecutionMode must be set to one of the modes above
	ExecutionMode string
}

Options to control the explain process

type TabletActions

type TabletActions struct {
	// Queries sent from vtgate to the tablet
	TabletQueries []*TabletQuery

	// Queries that were run on mysql
	MysqlQueries []*MysqlQuery
}

TabletActions contains the set of operations done by a given tablet

type TabletQuery

type TabletQuery struct {
	// Logical time of the query
	Time int

	// SQL command sent to the given tablet
	SQL string

	// BindVars sent with the command
	BindVars map[string]*querypb.BindVariable
}

TabletQuery defines a query that was sent to a given tablet and how it was processed in mysql

func (*TabletQuery) MarshalJSON

func (tq *TabletQuery) MarshalJSON() ([]byte, error)

MarshalJSON renders the json structure