dgraph-io/badger · error

Update can only be used with managedDB=false.

Error message

Update can only be used with managedDB=false.

What it means

db.Update is the user-mode (non-managed) transaction helper. When the DB was opened with WithManagedTransactions(true), Badger requires managed APIs (NewTransactionAt/CommitAt) and deliberately panics if Update is called, since implicit commit semantics conflict with managed version control. The check happens before any transaction is created.

Source

Thrown at txn.go:811

	if db.opt.managedTxns {
		txn = db.NewTransactionAt(math.MaxUint64, false)
	} else {
		txn = db.NewTransaction(false)
	}
	defer txn.Discard()

	return fn(txn)
}

// Update executes a function, creating and managing a read-write transaction
// for the user. Error returned by the function is relayed by the Update method.
// Update cannot be used with managed transactions.
func (db *DB) Update(fn func(txn *Txn) error) error {
	if db.IsClosed() {
		return ErrDBClosed
	}
	if db.opt.managedTxns {
		panic("Update can only be used with managedDB=false.")
	}
	txn := db.NewTransaction(true)
	defer txn.Discard()

	if err := fn(txn); err != nil {
		return err
	}

	return txn.Commit()
}

View on GitHub (pinned to 2a001d466f)

Solutions

1. Replace db.Update with db.NewTransactionAt(readonly=false) + explicit txn.CommitAt(ts, cb)
2. Or open a second DB instance without WithManagedTransactions for user-mode code
3. Audit call sites (populateEntries, updateLease, etc.) and convert each Update to the managed pattern

Example fix

// before
db.Update(func(txn *Txn) error { return txn.Set(key, val) })
// after
txn := db.NewTransactionAt(writeTs, true)
if err := txn.Set(key, val); err != nil { txn.Discard(); return err }
return txn.CommitAt(writeTs, nil)

if db.Opt().managedTxns == false {
    return db.Update(fn)
}
txn := db.NewTransactionAt(writeTs, true)
err := fn(txn)
if err == nil { err = txn.CommitAt(writeTs, nil) } else { txn.Discard() }
return err

When it happens

Trigger: Opening DB with WithManagedTransactions(true) and then calling db.Update(fn) (or db.View with the same pattern); caller of Update such as a helper like moveMoney or a subscription handler (updateLease) that assumes user mode.

Common situations: Enabling managed mode to control read/write timestamps (e.g. Dgraph integration, replica read streams) while leftover application code still uses Update/View helpers.

Related errors

• cannot use NewWriteBatch in managed mode. Use NewWriteBatchA
• Nil callback provided to CommitWith
• Cannot use NewTransactionAt with managedDB=false. Use NewTra
• cannot use NewWriteBatchAt with managedDB=false. Use NewWrit
• cannot use NewManagedWriteBatch with managedDB=false. Use Ne

AI-assisted analysis of dgraph-io/badger@2a001d466f (2026-09-05). Data as JSON: /api/errors/60b34eabd1d3dc9c. Report an issue: GitHub.