stages

Documentation

Overview

Package stages provides aggregation stages.

Index

• Variables
• func GetStatistics(stages []aggregations.Stage) map[Statistic]struct{}
• func NewStage(stage *types.Document) (aggregations.Stage, error)
• type Statistic

Variables

var Stages = map[string]newStageFunc{

	"$addFields": newAddFields,
	"$collStats": newCollStats,
	"$count":     newCount,
	"$group":     newGroup,
	"$limit":     newLimit,
	"$match":     newMatch,
	"$project":   newProject,
	"$set":       newSet,
	"$skip":      newSkip,
	"$sort":      newSort,
	"$unset":     newUnset,
	"$unwind":    newUnwind,
}

Stages maps all supported aggregation Stages.

Functions

func GetStatistics

func GetStatistics(stages []aggregations.Stage) map[Statistic]struct{}

GetStatistics has the same idea as GetPushdownQuery: it returns a list of statistics that need to be fetched from the DB, because they are needed for one or more stages.

func NewStage

func NewStage(stage *types.Document) (aggregations.Stage, error)

NewStage creates a new aggregation stage.

Types

type Statistic

type Statistic int32

Statistic represents a statistic that can be fetched from the DB.

const (
	StatisticCount Statistic
	StatisticLatency
	StatisticQueryExec
	StatisticStorage
)

List of statistics that can be fetched from the DB.