How to Use Badger (Embedded Key-Value Store) in Go

Database
2026-04-17T16:32:01+00:00
Badger is a fast, embedded key-value store written in Go that you use by opening a database instance, performing transactions for writes, and iterating over keys for reads.

Badger is a fast, embedded key-value store written in Go that you use by opening a database instance, performing transactions for writes, and iterating over keys for reads. It handles concurrency and persistence automatically, making it ideal for caching, session storage, or local data persistence without a separate server process.

First, install the library using go get:

go get github.com/dgraph-io/badger/v4

Here is a practical example showing how to open a database, write data within a transaction, and read it back:

package main

import (
	"fmt"
	"log"

	"github.com/dgraph-io/badger/v4"
)

func main() {
	// Open the database with default options
	db, err := badger.Open(badger.DefaultOptions("/tmp/badgerDB"))
	if err != nil {
		log.Fatal(err)
	}
	defer db.Close()

	// Write data inside a transaction
	err = db.Update(func(txn *badger.Txn) error {
		k1 := []byte("name")
		v1 := []byte("Alice")
		err := txn.Set(k1, v1)
		if err != nil {
			return err
		}
		return nil
	})
	if err != nil {
		log.Fatal(err)
	}

	// Read data inside a read-only transaction
	err = db.View(func(txn *badger.Txn) error {
		item, err := txn.Get([]byte("name"))
		if err != nil {
			return err
		}
		val, err := item.ValueCopy(nil)
		if err != nil {
			return err
		}
		fmt.Printf("Retrieved value: %s\n", string(val))
		return nil
	})
	if err != nil {
		log.Fatal(err)
	}
}

Key things to remember: always wrap writes in db.Update and reads in db.View to ensure transactional safety. Badger stores data on disk by default, so it persists across restarts. For high-performance scenarios, you can tune options like MaxTableSize or ValueLogFileSize in the badger.Options struct before opening the database. If you need to iterate over a range of keys, use txn.NewIterator with badger.DefaultIteratorOptions to traverse the dataset efficiently.