mgo vs mongo-go-driver

index-mgd.go

import (
	"go.mongodb.org/mongo-driver/mongo"
	mongooptions "go.mongodb.org/mongo-driver/mongo/options"
)

// createSlugIndex creates the slug index in Mongo collection
func createSlugIndex(ctx context.Context, c mongo.Collection) (err error) {
	ptrTrue := true
	ptrSlug := "slug"
	_, err = c.Indexes().CreateMany(ctx, []mongo.IndexModel{
		mongo.IndexModel{
			Keys: bsonx.Doc{{Key: ptrSlug, Value: bsonx.Int32(1)}},
			Options: &mongooptions.IndexOptions{
				Unique:     &ptrTrue,
				Name:       &ptrSlug,
				Background: &ptrTrue,
				Sparse:     &ptrTrue,
			},
		},
	}
	return
}

index-mgo.go

import mgo "gopkg.in/mgo.v2"

// createSlugIndex creates the slug index in Mongo collection
func createSlugIndex(c mgo.Collection) error {
	return c.EnsureIndex(mgo.Index{
		Name:       "slug",
		Key:        []string{"slug"},
		Unique:     true,
		DropDups:   true,
		Background: true,
		Sparse:     true,
	})
}